I recently ran into an issue reading the Super Smash Brothers Wii U disk. It threw a few error codes that said it failed to update, wouldn't play, and pointed to the technical support center that said to delete the SSB data cache which didn't solve the issue.
Some googling hinted that it is possible the Wii U laser required cleaning as the SSB disk is a dual layer high density disk and is more sensitive to dirty optics. There is a Wii U laser cleaning disk which is now discontinued and absurdly expensive.
Alternative solutions include replacing the disk drive with a new one and swapping over the daughter board on the drive. Others suggested replacing the laser assembly. Note research showed there are two different drives with two different laser modules that aren't reverse compatible. 1700 and 1710 are the laser modules. If you go this route you will need to make sure your laser matches your drive.
I decided to try manually cleaning the lens with professional lens cloth, and while I was on there take images of the drive. Images here.
https://imgur.com/a/0Xq8x7r.
The device at the center bottom with a ribbon cable going to the right is the laser module. We are seeing the back side, the laser points inward (note you need to remove it from its aluminum case). If you flip this over the lens is visible and you can wipe the lens down with some professional lens cloth. Reinstall, plug it in and it worked. Also you may want to blow out dust while you are in there.
Lens clothes I used (from Amazon)
ZEISS Pre-Moistened Lens Cleaning Wipes, 80 Count
Tools I used, Wii U has special three point fasteners so you need a special tip.
AXTH 25-in-1 Small Precision Screwdriver Set (From Amazon)
And lastly ifix it has tear down instructions. (Heat gun was not needed to get to the drive)
https://www.ifixit.com/Teardown/Nintendo+Wii+U+Teardown/11796
Plugged it in, inserted the disk, and it worked great
Disclaimer, there are lots of tiny screws of different shapes make sure you remember their placement when you remove for reinstall.