If something unexpected happens, check the program you submitted (by clicking on your browser's ``back'' button) to make sure it is correct. Did you issue a command like ``LOOP 60 { DELAY 60 }'', which will take an hour to execute? Did you SOURCE a file which SOURCEs another file which SOURCEs another file etc.?
The interpreter does a pretty good job of returning error messages in response to bogus commands, and the server tries to trap run-time errors intelligently and report on them. So the second place to look for problems is in the session log. If the server does not respond to a program, and if you're sure that the program is correct, it is possible that the network is down or that the server has crashed. In the latter case the server will have to be manually re-started from the console. One last place to look for clues is the WEBRTI log, which lives in the same directory as the WinHTTPD access log. It records every start and termination of WEBRTI and the commands issued to it.
Most Web browsers create local caches for efficiency, and browsers often retrieve documents from the cache rather than the remote source in the mistaken belief that the cache contains an up-to-date document. This can cause trouble for the sniffle user in certain situations, so consider clearing your browser's cache and disabling caching.
I doubt that any bugs remain in the WEBRTI program, but if you find one, mail tpkelly@cs.princeton.edu to report them. Be sure to include a detailed description of the problem. The easiest way to send me mail is to use my mail submission form: http://www.cs.princeton.edu/~tpkelly/.
Each set of commands submitted to the interpreter generates a separate session log, and these log files can be quite large. I once generated a 60-kilobyte session log with a one-line command. We don't want these session logs piling up on the server, so if there are too many of them the client is given an opportunity to delete all of them. Be sure to save any important session logs before doing this!
The WinHTTPD server communicates with back-end programs (like WEBRTI.EXE) via temporary files in server directory C:\WINDOWS\TEMP\. These temp files are normally deleted by the server after they are no longer needed, but in practice things can go wrong (e.g. the server can crash), and so these temporary files can accumulate. Purge them periodically.
Finally, it is a good idea to periodically de-fragment the server's hard drive to improve performance.