Blast from the Past Event: Blocked from Progressing (Crashing/..)

I'm stuck on week 2 -- The computer I used to build the first time travel thing was at the library, so they wouldn't let me repair it. I left the lot and came back and the computer has been replaced, but it won't let me check off the "repair or replace the computer". Also, my sim is an Elder - so the one hour of exercise keeps almost killing him, but it won't check off as complete! Please help.