You have the latest version of the OS installed. As well as this, you have either
- installed some -devel or "known to be naughty" software that's interfering with the device's basic operations or,
- changed some settings (possibly without knowing).

Assuming the device isn't damaged, look up in the Wiki and around this forum for how to get App Mgr working properly (NB good connection is strongly advised).

Worst case scenario: save all your important data and follow instructions on how to fully reinstall the OS. Sometimes much quicker than finding the underlying problem - especially if you've installed off-piste software!