I was testing an OS upgrade from Windows 2000 to Windows 2003 on a ColdFusion webserver earlier this week, and I experienced only one hiccup, although it was a momentary show stopper.

The ODBC services would not start, and although the “ColdFusion MX 7 Application Server” service was started, browsing ColdFusion pages received an odd error page:

500 NULL

There was a Macromedia TechNote about this matter, although it was unresolved as of the TechNote’s last update.

Whereas a Google search will uncover many other times this error may pop up, my circumstances applied after the OS upgrade and on every single page view in its entirety.

The TechNote gives a good hint when it says the error can be caused by an empty or missing license.properties file. My answer was similar: The user that the ColdFusion service was running as didn’t have permission, after the upgrade, to read from the CFusionMX7 directory.

I gave the user read rights and everything began working wonderfully.