This can be caused by corrupted preferences or other cached files.

Here is an updated solution based on a forum post for this problem. 


Perform these steps while Adobe Animate is not running.

1. Press the Windows key (to the left of the spacebar looks like the Windows logo) + R at the same time. This opens the Run dialog.
2. Type in %appdata% and hit enter.
3. Open the Adobe folder, find Adobe Animate, Animate, and Animate Common. Delete these folders. 

4. Open Run as we did in step 1.
5. Type in %localappdata% and hit enter.
6. Open the Adobe folder, find Adobe 2024. Delete this folder. 

Forum post pertaining to this issue: