RCINT failure. String Table ID not found. 45 at line 131

I have installed Logon Studio on my XP machine, and I have been using it for over a year now without any errors.
Today, when I try to change my logon it gives me the error:

Error:
Parser Message
RCINT failure. String Table ID not found. '45' at line 131
OK
Tried changing using other logon but gives me the same result. I have also uninstalled and re-installed Logon Studio but to no avail. Can anyone help me?
Thanks!
