Sharp mx-5112

The printer stopped printing cyan and magenta.
After the printer's receipt from the toner, I got an error l4-11.
I tried to remove the error by pulling out the paper exit unit and installing it in place.
After these operations, the device went into the error "Close upper right side cover" on start display.
Can't find this cover in manual. (all cover closed)

I think it's a "Upper cabinet right" but I can't see any sensor (maybe in just blind)

Please tell me where to look to remove the error