I can't in any way modify my saved document?

It's saved with the krita file extension and the layers are as they were when I saved it, but I can't erase anything or draw on the document.

I'm on the right kind of layer; there's no stop-sign, just the standard brush icon. My layers are all visible and unlocked and I can't draw or erase from a single one of them. I can't make shapes; none of the tools are working. It's just on this document though; I've made a new canvas and I can draw just fine on that one, as well as on the scratchpad, but my saved work can't be changed.

Please help!

Thanks.

My best guess is that you need to deselect your selection.

Krita saves selections to the file, you see