HTTP 500 error after upgrade

Greetings,

I stepped through the upgrade chain from 7.1.x to 7.9.4. After the upgrade process, when I click on a document to view it in the documents module a new tab opens, yielding an HTTP/500 error. I’ve reviewed the suite CRM log, even on info level, and I’m not able to see what the problem is.

I verified that file ownership and access permissions look good, as well - all files/directories are user:group for www:www, and permissions are rw for user and group. All directories are +x.

Any suggestions on where to look next, or how to solicit a better error from SuiteCRM? The Apache log wasn’t useful either.