Delete the user you are under files:
PDX_EN_FULL_bars.cfg
PDX_EN_FULL_sbar.cfg
(I usually delete them under all users)
They can be in “hidden” folders.
C:\Users\[username]\AppData\Roaming\Corel\Paradox100\ConfigDir
They can be elsewhere, but the user ones are often the problem.
Delete all .lck files.
Open the library in design and verify it no breakpoints. Verify Compile with warnings and Compile with debug are unchecked.
Save.
Reboot.
Test.
Is it just one library?
If so, deliver that library and remove lsl, see if runs normally delivered.
Make a new empty library, does it do that to it?
Next option is to make new library and move procs and methods a few at a time and test.
If it is just that library.
Right, I was about to suggest that.
The odd thing is that when that is checked, forms do not open in design by default?
Only libraries.
Maybe because the library is really opened “in design mode” as it has no GUI, and all this does is open a debug window?