"Case does not exist or has been deleted" / Editing cases fails

Symptoms:

Solution:

This sort of weird behavior can result from lost permissions that setup put in place but that have bene subsequently removed somehow. On a command line, navigate to the FogBugz folder. Enter these commands to grant permissions such that the user account under which Apache is running can access everything it needs:

chgrp apache FileUploads
chmod g+rw FileUploads
touch Accessories/application.data
chmod g+rw Accessories/application.data
chgrp -R apache Website Accessories
chmod -R g+r Website Accessories
chmod +x Accessories/dispatchod

Details:

When the apache user does not have the needed permissions, some of the database interactions can fail, or fail part way through, leaving the edit incomplete. Note that if a case has a null value for its Priority, the case cannot be shown because this type of state is a corrupted state for a case to be in. This is when FogBugz says it "does not exist or has been deleted".