Looks like a problem with the cache.<br /> Such a naming convention is used to name files that Firefox stores in the browsing cache. You can try to clear the cache. * "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now" ---- Start Firefox in [[Safe Mode]] to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). * Don't make any changes on the Safe mode start window. See: * [[Troubleshooting extensions and themes]]