I can't use any GRASS tool, I get the error "The following layers were not correctly generated"

Question

I've been trying to use GRASS r.fill.dir to get a filled DEM but I get the error:

The following layers were not correctly generated.

I tried using SAGA Fill Sinks, that worked. I get the same error on every GRASS tool I use.

QGIS version 3.12.0-București