Can't set data usage warning/limit I have a problem with my Nexus 5 (running Android 5.0 but I already had this problem on 4.4.4)

I played around with the slider for mobile data limits and warnings and it got out of range... My warning now is at 719.806.528 GB and my data limit is also out of range. 
Does someone know which app's cache do I have to delete to get this to 0 GB again?

Thanks and best regards

Josef
Try clearing defaults, cache and data(memory) for the dataUsage app.

You could also simply uncheck the "set mobile data limit button" except you really need to use it. You can also try returning the slider to zero.