Why are apps crashing when they are starting?

[Windows Central Question]

Facebook, Whatsapp, even a small app like Fitnesster and more are crashing when they are starting. I searched on forums which said to restart my phone.Well... restarted it not once but twice and it is still not working(First time I put a copy of a previouse version of my phone and the second time I made a fresh restart to the fabric settings). I deleted maaany photos which were important and it was for nothing???Really, there must be a way to resolve that and if you know please help.

 

[Maurizio Troso]

Facebook, Whatsapp, even a small app like Fitnesster and more are crashing when they are starting. I searched on forums which said to restart my phone.Well... restarted it not once but twice and it is still not working(First time I put a copy of a previouse version of my phone and the second time I made a fresh restart to the fabric settings). I deleted maaany photos which were important and it was for nothing???Really, there must be a way to resolve that and if you know please help.

As notebooks, simply uninstall and reinstall. (remember making backup in Whatsapp fist)

Which phone and windows build?

 

[iKadin]

I tried five times to reinstall the apps and no difference. Nokia Lumia 520 and Windows phone 8.1 (Vintage, I know). Yea, I am the same person

 

[Chintan Gohel]

I tried five times to reinstall the apps and no difference. Nokia Lumia 520 and Windows phone 8.1 (Vintage, I know). Yea, I am the same person

try do a factory reset and then set up your phone afresh - install a few apps and test