i have an old Samsung Galaxy S5 which is still running on Android 6.0/Marshmallow & recently it's giving me some issues; and finally found the solution.
Initially..this S5 phone kept rebooting/restarting by itself. I did a Factory Reset but it did not work. Not to forget..it heats up badly & battery drainage was really bad.
Whenever I tried to download/update apps from Playstore..it kept giving me this error:
Insufficientstorage This device doesn't have enough storage to download "Android System WebView. Consider deleting apps or content that you no longer need and try again.
And whenever i tried checking further via
Settings>General>Storage>
It kept showing eitherComputing orCalculating onUsed Space, Other & Cached Data.
Solution: Removed SD card & reboot the device.
Ever since i did the above..everything is back to normal. No more random rebooting, heating problem & no more issues of installing/updating via Playstore.
I had this S5 device long time ago & it still serves as my backup phone using Msim.
It seems that SD cards do wearoff or get corrupted after some time.
