If anyone has a tumble/condensing dryer at home and you start getting drain/pump errors you probably have this issue:
I have a different model than he does but mine was almost exactly the same in terms of opening and the issue, the lint sludge in the trap at the bottom. Started getting pump errors after about 10 minutes of drying. Did this and vacuumed/wiped down the sump and venting inside. Works like brand new now
If you have any sort of ability using a screw driver you can do this