Under Processor Status on the left side of you RSLogix500 software click on this and select the error tab. That will tell you your error and then you can also search the help files for the error code.
Hope this helps.
I assume the xx mean 00 and from the help files...
0025 There are excessive JSRs in the STI subroutine. This non-recoverable error occurs at run time.
RSLogix 500 - Copyright Rockwell Software 2000, 2001, 2002