No the PLC doesn't need to be in a specific mode in order to upload, Run mode or Stop mode either is fine.
If you know which version of Visilogic the program was originally written in you can try using it, however a newer Visilogic will upload a project written in an older version.
As for the run-time errors, I haven't ever had that issue. I'd suggest taking screen shots and sending and email to support@unitroincs.com.