New exception dialog has problems with long message

This is the code to reproduce it:

EXEC RAISE_APPLICATION_ERROR( -20000, LPAD( '123456789 ', 4000, '123456789 ' ) );

This is the result:


There is a maximum error message length set by Oracle. You can see the truncation in SQL*Plus using your example and the same corruption in older Toad using the old dialog if you scroll to the bottom of the error message. I've changed it to truncate the error message at the length limit and append '...' if the message has been truncated. This is in place for the next beta.