[Bug]: Disabling UI elements sometimes throws NPE errors

### Apache Hop version?

2.18.1

### Java version?

21

### Operating system

Windows

### What happened?

When using the system to disable UI elements in some cases when this element is then referenced somewhere we get an NPE.

The goal here is to create a generic UI test with SWT bot and track these issues down.

### Issue Priority

Priority: 2

### Issue Component

Component: Hop Gui