User Profile Service service failed the sign-in
User Profile cannot be loaded
Sometimes this error occurs for no apparent reason, one user was able to login to the PC and afterwards another tries and will always get this error until it is fixed.
On the PC that is affected you want to open file explorer and go to:
You will see a folder called "Default" that you want to rename to something like "_Default"
Then copy over from another PC running the same version of windows the folder C:\Users\Default and place it back in C:\Users on the affected PC.
After doing this the user will be able to login again.