Why apps or play store not starting?

[kallen2143]

Samsung Galaxy 10.1 GT-P7500 16Gb, Android version 4.0.4 was working fine, no changes or updates, now Play Store, YouTube, Maps and all downloaded games do not start. No error messages I can see. Internet browsing is fine.
Completely new to Android, but any clues appreciated

 

[B. Diddy]

Welcome to Android Central! Does this persist after a reboot?