Whenever I go to certain topics/forums when I'm logged in such as General, Tires, and a few others, the following error comes up. When I log out, I can view the forum posts.

Sorry, UBB has encountered an unexpected, fatal error. This error is extremely abnormal. Please contact the board administration. The error text is:

Can't open 'NonCGIPath/cache-(cache_pw)/ubb_files/forum_page/Forum1/forum1-5.cgi'.

The exact error returned by the operating system is:
Input/output error

Will you please fix this so I don't have to log out in order to read certain forums?

Thanks!