I am working on a piece and odd things just happened.

Things were going fine until I began using the transform and selection tools. My reference image and the tools that go with it just vanished. Also: I can no longer paint on any layers. It's as if they are all locked, but they are not. The transform tool isn't acting right at all.

I closed the document and opened it again. Then I closed Krita and re-opened it. Same thing. What could be the problem?

Hard to guess without a screenshot or access to the document itself. What do you mean with "the tools vanished"? Are you sure the content of the transformed layer isn't just outside the canvas borders? If you hover over the layer's thumbnail in the Layers docker, does the big preview show anything? Do you have a (hidden) selection active? Is the layer opacity at 100%? Are any of the layers alpha locked, or do they have a mask / filter on them that influences the opacity? Are you trying to modify something else than a (bitmap) Paint Layer?

What Krita release are you using anyway?

Thanks for responding. I can't figure out what happened so I just made the illustration again. I am using version 4.2.2. The "wonkiness" did not repeat.