When creating the package tree, dot files are ignored for packaging. However, there is an action to un-ignore dot files.
For example, if the content to be packaged contains a git repository, and the intent of the user is to package the repository, they will need to un-ignore the .git directory in the tool.
However, the tool does not allow you to do this; an error is received: "Unable to unignore node, because tree would become invalid please correct tree before unignoring." Unfortunately, there's really nothing the user can do to "correct the tree".

This is a bug, and ought to be corrected. The user should be able to un-ignore a node in the tree, and the PTG should create a valid tree without requiring user input.