Occasionally I will get a spate of key 1 errors. Bit of wiggling of USB cables can sometimes cure it, today it did it mostly all day, but hasn’t been like that for a while, comes along in spates. Going to order a new USB 2 to microUSB cable for connecting to Ender 5 plus. Although it does give the error more on the 5+ it has done it on the SE too. Read on reddit something about disable WIFI and IOT (??), can’t find in advanced setting how to disable WIFI or IOT (whatever that is)
Looking like there is something that it is not liking in the geometry of the part. It is nothing special as a part (an open top box) but it seems to crap out at 7% every time. Reslicing it, no change. Change some of the STL parameters, reslice, no change. Continue the print after a couple more Key1 errors and it will be fine once it gets to 8% and finishes the print. Most odd.