The Regen Compiler Errors window may appear when you have performed a Regen in the Object Directory and for some reason a compile error occurred. Perhaps an object it refers to has changed and no longer supports a function being called.
The OK button closes the window without doing anything.
The Copy To button allows you to save the messages to a text file.
The Print button prints the messages.
The Clipboard button sends a copy of the messages to the clipboard.