Err1 indicates a door not closed in the documented Haier all-in-one units. Keep in mind Err: E1 without that prefix refers to drainage in the same table.
The distinction is listed in the Haier Appliances table for washer-dryers. Confirm the model before applying the match.
Check what is preventing the door from closing
With the drum stopped and the door released, move away any garments that may be caught between the edge and the gasket. Check whether the load is pushing the door from the inside. Close it normally, without slamming or applying continuous pressure on the latch.
If you see a damaged handle or latch, stop trying. A complete mechanical closure alone also does not confirm the electrical detection needed to start.
If the warning appears during a cycle with water in it, do not force the door open just to repeat the inspection. Refer to the model recovery procedure and request service if Err1 returns with the area cleared. Do not bypass the door switch.
Note whether the unit managed to start or whether Err1 appeared on the first attempt; include a photo that preserves the prefix.