Hi,

Try performing a factory reset on your tablet.

Be aware that a factory reset will erase all your user data and downloaded apps. It will restore your tablet to a factory default condition. It will be like when you first bought it.

Before you perform a factory reset:

Ensure that the battery is charged.

Do not leave the charger plugged in when you perform a reset.

Remove the external SD Card (if any installed)

Here is a link that shows how to perform a factory reset.

https://www.youtube.com/watch?v=QoiLEpT3...

Be patient, it takes a little while for the reset to complete.