[iDVBUG] Desktop paint tab not functioning properly after loading new data

[maystey]

Describe the bug
After loading a data file that is too large to paint, the paint tab does not function properly after loading new data.

To Reproduce
Steps to reproduce the behavior:

1. Load a data file that is too large to use the desktop paint feature
2. Open the Paint tab (it should tell you that the file is too large to paint)
3. Load a new data file (small enough to use the pain feature)
4. Open the Paint tab which is not functioning properly (see screenshot bellow)

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots

Attach debug logs:
I don't have access to the logs at this moment, but I don't recall seeing any exceptions in them.