FAQ: Can the VBA IDE be opened if my zenon project includes Cyrillic characters in the VBA code?
The VBA IDE cannot be opened on a windows system without selecting the Russian language first. You will get no error message, it simply does not open. To open the VBA IDE with a project that includes cyrillic characters, you need to set the language for non-unicode programs to "Russian - Russia", then the VBA IDE will open normally.