Hummingbird was re-checking files and wouldn't finish (waited for 2 hours!).
Did the following:
1. Tried refreshing page - no result
2. Tried deactivating Hummingbird from plugin page - result: website is currently unable to handle this request. Unable to visit plugin page
3. Manually deleted Hummingbird via ftp - now I can load plugin page again
4. Reinstall Hummingbird but gets stuck again. Have to manually delete Hummingbird again to get to plugin page (both main and WPMU Dev Dashboard)
Short of rebooting my server, what can I do?