I have a problem with RSLogix5 when I am online (DH+) with one processor and try to go online to another without first saving. The software prompts me to save, to which I respond with "yes". Then it prompts me to upload data tables before saving which I also respond yes. It seems to upload and save the file fine, then, just before connecting to the other processor, RSLogix will error and immediately shut down. I now have the habit of saving the file first (CTRL+S or mousing to the File Save menu) before selecting another processor to go online with. Then I don't get the error. I think it's a timing thing between saving a file and changing the DH+ connection. This is different than your problem, but the point is this: You may try a different method of executing the save command to see if you get the same error.
Another thing I have seen cause Windows/RSLogix errors is a corrupted database. Try exporting the database as ASCII (csv file). Then move or delete the old RSS file. Go online and upload the program, import the database from the csv file to get all your comments back, then try saving it.
Hope this helps, and let us know if you figure it out. These software quirks can be rare and solutions even more rare. It's nice for the rest of us to see possible solutions that we can search for later when the problem recurs.
Thanks
Paul C.