Why has the adjustment brush in my LR 5.7.1 stopped working?

[neilh55354168]

I can use it to edit photos then all of a sudden it will cease to function. I can go out of LR and back and it stays dead. Sometimes changing catalogs will work for a bit then stop. Very erratic.

[ManiacJoe · Accepted solution]

Check the brush's flow and density settings, push them towards 100 if need be.