Hi, usually this means that you have a file that is corrupt usually due to a virus or damaged file. The way to cure it is to wipe it out with a system reset and it will work as good as new again. Note you will lose all data you have stored so you shoudl back it up or just let it wipe clean(recommended) and start fresh;-)
Please see this page for instructions on doing all of this .
In any case, I will stick with you until this is complete.
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