Polygon creation fails: “The feature cannot be added because it's geometry collapsed due to intersection avoidance”

Question

From one moment to the other I cannot create any polygon anywhere on the map, independent from the layer I am in, even if I create a new shape-file. I have checked all snapping options, enabled them, disabled them completely, restarted everything, etc. but no matter what I do this message pops up:

The feature cannot be added because it's geometry collapsed due to intersection avoidance

It's super weird because even if I create it in absolutely blank space it tells me that the geometry collapsed. It occured when I had print composer open and modified a polygon. I moved the knots of one polygon and then wanted to create a new one which did not work. I checked the polygon of which I had moved the knots 400 times...there is no flaw and no intersection. Frustrating.

I am using QGIS 3.4 Madeira

Answer 1

Managed to solve it myself. I had a disabled layer that encompassed the entire country (country contour). For some reason, maybe when testing out the snapping features a while ago "avoid intersection" was still enabled. The confusing point for me was that I had disabled snapping altogether so I had thought this would also disable all "avoid intersection" boxes that I had enabled in advanced snapping configurations. However I had to uncheck them individually even though snapping was turned off all together. Dont really know if this is intentional by the developers, but anyway. Lesson learned.