When Chess Openings Wizard opens a new windows under Windows 10 or Windows 8.1, Windows will show an error message such as:
Access violation at address 758F894E in Module 'user32.dll' Read of address 000000C0
Windows recovers from this error and the program continues to work properly after that. Nothing can be done to prevent the error message and it is annoying even if it doesn’t cause any real problem with Chess Openings Wizard.
The new version currently being tested does not trigger this error in Windows 10.