I've sent the full error log to your email. Yes, the error is reproducible every time by just pressing Control + G. After pressing OK on the error pop-up, the expected dialog for the GoTo Line is displayed. Thanks a lot for your quick help!
Thanks. I cannot reproduce it, but I see the issue based on the call stack and our commit history. The fix will be in next Monday's beta if you can give it a test. Toad for Oracle 17.1 Beta - #36 by JohnDorlon