For a while today, Word Press was throwing an odd error:
Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0
I saw this shortly after making three changes–I installed Smedberg’s Atom 1.0 plugin; I’d been playing with directory permissions on my host (Hosting Matters, if it matters); and I’d installed the Java plug-in.
The key turned out to be disabling Java and restarting the browser. Oddly, just to test, I re-enabled Java, and the problem has not yet recurred.
Submitted as a comment here.