Apps crashing on opening

If its an app which worked and suddenly just started crashing its probably because there is a open process of this app that stopped working. just kill it and restart the app. I'm using tasm manager to do that quickly.

are the crashing - forced close - or are they just "going away"?if it is the latter, push your back button and try again, sometimes it seems to stick (as well as the other buttons) I believe this is a software issue.

Try installing aLogcat or similar log viewer and check logs immediately after the crash. I'm currently having similar issues second time in a row, reflashing helped for a couple of weeks. Looks like something has corrupted some part of the directory structure as I keep getting (for example from aldiko):sqlite3_open_v2("data/data/com.aldiko.android/databases/catalog.db", &handle, 6, NULL) failed and then just Force Close. This just started happening, first with 0809 and now with the rooted repack.

I had a similar problem with my A81 after letting the battery go completely dead. then booted again with a low battery. Suddenly my IReader, System Info and Browser all stopped working. I was able to uninstall and then reinstall to resolve the I-Reader, but I had to reflash in the end to fix the problem browswer (Opera). I think Janekq is on the right track in my instance. Post more details about the scenario and what you may have done or installed immediately before it started. Lots of times it is something related to a problem app or behaviour.