Thank You UJ95x
Impressed by your prompt response I decided to join the forum [I started this thread as a guest].
I managed to enter Recovery mode [using a different sequence of buttons (an idiosyncrasy of the
Koodoo Canada T989D)].
Cleared the cache partition as suggested. Unfortunately this did not solve the problem. However, I downloaded an app [CM Browser] that works flawlessly with Facebook. Nevertheless, I would appreciate more feedback on the original facebook app's problem.
PS: Really impressed by response speed (and your signature from Carl Sagan's Demon Haunted World)