diff --git a/build/scripts/linux/build-avalonia-packages.sh b/build/scripts/linux/build-avalonia-packages.sh
index 6a35814..8a3b868 100644
--- a/build/scripts/linux/build-avalonia-packages.sh
+++ b/build/scripts/linux/build-avalonia-packages.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"
 PROJECT_PATH="$REPO_ROOT/src/GregModmanager.Avalonia/GregModmanager.Avalonia.csproj"
 OUTPUT_ROOT="${1:-$REPO_ROOT/artifacts/avalonia-linux}"
 VERSION="${2:-1.1.0}"
diff --git a/src/GregModmanager.Core/Services/TelemetryService.cs b/src/GregModmanager.Core/Services/TelemetryService.cs
index 8531b66..648dded 100644
--- a/src/GregModmanager.Core/Services/TelemetryService.cs
+++ b/src/GregModmanager.Core/Services/TelemetryService.cs
@@ -99,7 +99,7 @@ public async Task TrackEventAsync(string eventName, object payload, Dictionary<s
         var message = payload switch
         {
             SyncCollectionEvent sync => JsonSerializer.Serialize(sync, AppJsonContext.Default.SyncCollectionEvent),
-            _ => JsonSerializer.Serialize(payload, payload.GetType(), AppJsonContext.Default.Options)
+            _ => JsonSerializer.Serialize(payload, typeof(object), AppJsonContext.Default)
         };
 
         await PushToLokiAsync(eventName, message, labels);
diff --git a/tests/GregModmanager.Tests/Services/UploadDependencyCheckerTests.cs b/tests/GregModmanager.Tests/Services/UploadDependencyCheckerTests.cs
new file mode 100644
index 0000000..680f581
--- /dev/null
+++ b/tests/GregModmanager.Tests/Services/UploadDependencyCheckerTests.cs
@@ -0,0 +1,502 @@
+using GregModmanager.Models;
+using GregModmanager.Services;
+using GregModmanager.Steam;
+
+namespace GregModmanager.Tests.Services;
+
+public class UploadDependencyCheckerTests : IDisposable
+{
+    private readonly string _tempPath;
+
+    public UploadDependencyCheckerTests()
+    {
+        _tempPath = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+        Directory.CreateDirectory(_tempPath);
+    }
+
+    public void Dispose()
+    {
+        if (Directory.Exists(_tempPath))
+        {
+            try
+            {
+                Directory.Delete(_tempPath, true);
+            }
+            catch
+            {
+                // Ignore cleanup errors in tests
+            }
+        }
+    }
+
+    private WorkshopMetadata CreateValidMetadata()
+    {
+        return new WorkshopMetadata
+        {
+            Title = "Valid Title",
+            Description = "Valid Description",
+            Visibility = "Public",
+            Tags = ["Tag1"],
+            PreviewImageRelativePath = "preview.png"
+        };
+    }
+
+    [Fact]
+    public void Check_MissingContentFolder_ReturnsError()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Content folder" && r.Severity == UploadCheckSeverity.Error);
+        Assert.False(UploadDependencyChecker.IsReadyToUpload(results));
+    }
+
+    [Fact]
+    public void Check_EmptyContentFolder_ReturnsError()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Content folder" && r.Severity == UploadCheckSeverity.Error);
+        Assert.False(UploadDependencyChecker.IsReadyToUpload(results));
+    }
+
+    [Fact]
+    public void Check_MissingNativeConfigJson_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "config.json" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_PresentNativeConfigJson_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "config.json"), "{}");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "config.json" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    public void Check_EmptyTitle_ReturnsError(string? emptyTitle)
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Title = emptyTitle!;
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Title" && r.Severity == UploadCheckSeverity.Error);
+        Assert.False(UploadDependencyChecker.IsReadyToUpload(results));
+    }
+
+    [Fact]
+    public void Check_LongTitle_ReturnsError()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Title = new string('A', SteamConstants.MaxTitleLength + 1);
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Title" && r.Severity == UploadCheckSeverity.Error);
+        Assert.False(UploadDependencyChecker.IsReadyToUpload(results));
+    }
+
+    [Fact]
+    public void Check_ValidTitle_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Title" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_EmptyDescription_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Description = "";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Description" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_LongDescription_ReturnsError()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Description = new string('A', SteamConstants.MaxDescriptionLength + 1);
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Description" && r.Severity == UploadCheckSeverity.Error);
+    }
+
+    [Theory]
+    [InlineData("Public")]
+    [InlineData("FriendsOnly")]
+    [InlineData("Private")]
+    public void Check_ValidVisibility_ReturnsOk(string visibility)
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Visibility = visibility;
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Visibility" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_InvalidVisibility_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Visibility = "InvalidVisibility";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Visibility" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_MissingPreviewImage_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PreviewImageRelativePath = "preview.png";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Preview image" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_LargePreviewImage_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PreviewImageRelativePath = "preview.png";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        var previewPath = Path.Combine(_tempPath, "preview.png");
+        // Create a fake large file using sparse file if possible, or just write some data.
+        using (var fs = new FileStream(previewPath, FileMode.Create, FileAccess.Write, FileShare.None))
+        {
+            fs.SetLength(1_048_576 + 10);
+        }
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Preview image" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_ValidPreviewImage_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PreviewImageRelativePath = "preview.png";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        var previewPath = Path.Combine(_tempPath, "preview.png");
+        File.WriteAllText(previewPath, "fake image content");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Preview image" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_EmptyTags_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Tags = new List<string>();
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Tags" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_ValidTags_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Tags = ["Tag1", "Tag2"];
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Tags" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_FirstPublishEmptyChangelog_ReturnsError()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PublishedFileId = 0;
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata, changeLog: "");
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Changelog" && r.Severity == UploadCheckSeverity.Error);
+    }
+
+    [Fact]
+    public void Check_UpdateEmptyChangelog_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PublishedFileId = 12345;
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata, changeLog: "");
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Changelog" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_ValidChangelog_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.PublishedFileId = 12345;
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata, changeLog: "Initial release");
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "Changelog" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_GregFrameworkDependency_NeedsGregWithoutDescription_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Needsgreg = true;
+        metadata.Description = "Some standard mod without mentioning the framework";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "GregFramework (greg)" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_GregFrameworkDependency_NeedsGregWithDescription_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Needsgreg = true;
+        metadata.Description = "This mod requires gregCoreModFramework to work.";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "GregFramework (greg)" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void Check_GregFrameworkDependency_DoesNotNeedGregButMentionsIt_ReturnsWarning()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Needsgreg = false;
+        metadata.Description = "This mod is similar to gregCoreModFramework.";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "GregFramework (greg)" && r.Severity == UploadCheckSeverity.Warning);
+    }
+
+    [Fact]
+    public void Check_GregFrameworkDependency_DoesNotNeedGregAndNoMentions_ReturnsOk()
+    {
+        // Arrange
+        var metadata = CreateValidMetadata();
+        metadata.Needsgreg = false;
+        metadata.Description = "Standard mod without any mentions.";
+
+        var contentDir = Path.Combine(_tempPath, "content");
+        Directory.CreateDirectory(contentDir);
+        File.WriteAllText(Path.Combine(contentDir, "somefile.txt"), "test");
+
+        // Act
+        var results = UploadDependencyChecker.Check(_tempPath, metadata);
+
+        // Assert
+        Assert.Contains(results, r => r.Label == "GregFramework (greg)" && r.Severity == UploadCheckSeverity.Ok);
+    }
+
+    [Fact]
+    public void IsReadyToUpload_NoErrors_ReturnsTrue()
+    {
+        // Arrange
+        var results = new List<UploadCheckResult>
+        {
+            new UploadCheckResult { Label = "Test", Severity = UploadCheckSeverity.Ok, Detail = "" },
+            new UploadCheckResult { Label = "Test", Severity = UploadCheckSeverity.Warning, Detail = "" }
+        };
+
+        // Act
+        var isReady = UploadDependencyChecker.IsReadyToUpload(results);
+
+        // Assert
+        Assert.True(isReady);
+    }
+
+    [Fact]
+    public void IsReadyToUpload_WithErrors_ReturnsFalse()
+    {
+        // Arrange
+        var results = new List<UploadCheckResult>
+        {
+            new UploadCheckResult { Label = "Test", Severity = UploadCheckSeverity.Ok, Detail = "" },
+            new UploadCheckResult { Label = "Test", Severity = UploadCheckSeverity.Error, Detail = "" }
+        };
+
+        // Act
+        var isReady = UploadDependencyChecker.IsReadyToUpload(results);
+
+        // Assert
+        Assert.False(isReady);
+    }
+}