Good afternoon 3D people!
I’m new to this. Gaining experience fast. Today I had my first runout mid-print. I was so close!
I’m looking for solutions to this and I’m surprised there isn’t much discussion of it. One post implied that if one started from a jump drive (instead of downloading the file over WIFI?) the print would stop and you could unload/reload and be on your way.
This raises 3 Questions: 1) does this really work?, 2) why would that be different than starting with a downloaded file? And 3) where is this documented? I clearly need to be reading from this source. This would have been good to know.
The filament runout sensor should work for any file whose printing is started from the touchscreen, regardless of how it got there—it’s worked for me with files transmitted over wifi (note, however, that my A150 still has its original Kickstarter-era firmware, so yours may have a different set of bugs). It doesn’t work if you’re puppeting your Snapmaker over the USB mini-B port using Octoprint or the like. I don’t have any experience with the case where the job is started from Luban, since the old firmware won’t do that, but someone else will probably chime in with the necessary information within the next few hours.
You kind of have to dig into the forum for this kind of information, as it often isn’t mentioned in official sources. It can also be worth checking the github repositories for bugs if you’re looking at something that might be a software problem.
Well, it turns out it did. It came up with a screen that said runout recovery confirm (or something to that effect). I confirmed, but it didn’t start again. I looked for instructions on what to do when it says that but couldn’t find them.
I ran the head down to the top of the print and edited the G-code to remove the code up to that Z-height. It’s running now so I’ll be able to report whether this worked. It started well enough, but I couldn’t tell if it was laying down filament.
What I really want though, is the steps required to continue the print. I must have taken a mistep after the confirm message.
I remember it as being entirely straightforward with no non-obvious steps required, although it’s been a while since it last happened to me. Either you hit a firmware bug, or the nozzle or bed had cooled and needed to heat up again. I don’t remember anyone mentioning this specific bug on here before, but it’s possible that they have and I’ve just forgotten. 
Update, the work around I used, editing the G-Code worked. So the immediate issue was dealt with. It could be that the equipment cooled.