Hello,
Has anyone had an issue with the ultimaker drawing the filament back when it is in the middle of printing a layer? It is doing it at the moment, which causes it to miss parts of the print and normally get clogged up when filament starts coming out again. 
Seem to have made it better - reduced the flow on the print to 70%… for the first layer
This is called retraction, it’s mean to do this, but it might be doing it too much depending on settings, or the knurled bolt may be blocked up, the filament could be inconsistent sized, or the extrude temperature might be wrong.
Yeah. It seems to be fine after the first layer. Managed to do one print with no problems whatsoever, but then couldn’t do anymore. Was wondering if it was retracting during the first layer as it was detecting it was getting too clogged in the head (not sure if it has the capability to do that)? Setting to 70% for the first layer and then putting it back to 100% seems to have solved the issue.
Depending on the software the first layer(s) can be treated differently as you’ve noted, so sounds like you’ve sorted it.
She’s pretty old and it would be worth someone reaching out to Ultimaker to see if the agreement could be renewed, it’s been a fantastic donation, but it was from 2014.
She still goes well. Only problem is the trains - they really rattle the bed when they go past. The isolators and taking it off the bench that it’s on (attached to the wall) helps a little.
Interesting, didn’t used to be an issue.