I have been searching online for problem similar to my case but unfortunately didn't manage to find any solution to my case.
Samsung Galaxy S2 i9100T droid version 4.03
I didn't do anything, never took out the SD card, or rooting or factory reset whatsoever all this time and my phone was working fine. But then today suddenly when I reached out for my phone to read one whatsapp message, some kind of error message shown up and need me to close it I think. I can't really remember what its saying, not just for whatsapp but along with several other apps.
Then I restarted my phone, and found in my home screen several shortcut icons missing, some are still there but with android logo. So I went to the main menu and noticed all the apps are there but it became gray colored with the same icon (Android with SD text on right corner).
When I pressed the app a message saying the app is not installed on the phone.
Another important thing is that I am unable to locate the google play store anywhere, even under the Setting->Apps->All. Actually, I can't find all the missing applications -- though in main menu I saw the gray colored play store icon (not google play but play store)
I don't think the SD card is the problem since my music and images are still there just fine, not to mention a few games apps still working fine even though they are also stored in SD.
Just now I tried to access google play store with internet browser on phone and tried to download the missing apps again but I can't, it gives the message
your device already has this item. Even if I want to un-install the missing apps, I can't because I cannot locate them under Settings->Apps->All.
What do I need to do to fix this problem? I really have no idea since I am one that never really follows up with tech development of mobile phone, just take it and use it for granted.