You will get Active Server Pages error 'ASP 0126' if you try to include a file that does not exist. This is a straightforward error - that file is not on your server!

Do a response.write of the include file name rather than including it, to make sure you really know what file you are planning on including. Then check to make sure that include file exists on your webserver. If it really does exist, check its permissions to make sure that it is available to the process that is trying to access it.

Be sure to read about the Include Statement to make sure you are using it properly.