Firefox 38 is the beta version of Firefox, so many add-ons won't work properly on it. if you don't care to help test beta versions, it's easy to switch to the regular release of Firefox. Just go to https://www.mozilla.org/en-US/firefox/all/ and download the correct language.

Notknow said

Trusteer Rapport tells me they now support Firefox 37. I am no computer whiz-kid and do not dare to just download the 37 version without guidance of somebody more experienced. I would greatly appreciate the help of a patient "tutor". I am running Windows Vista. Thanks in advance

Thank you very much. Downgraded successfully! Trusteer Rapport is back!