The most likely thing is that, in the Paint panel, the duration for the paint strokes is set to "Write On" (see screenshot below). This means that the paint strokes are revealed/animated just as you drew them in time. The reason why you don't see anything is... because you are standing at or before the point in time in which you started drawing the stroke. If you move the CTI/playhead to a later point in the timeline, you should see the paint strokes revealing.
If you want the paint stroke you already created to be displayed consantly rather than write on, you can make sure the "start" and "end" parameters for that brush's stroke options in the timeline are set to 0 and 100 per cent respectively.
Another possibility: the paint strokes have bars to show their location in time, just like layers have. Is it possible that the paint stroke bars are at a different time from when you're standing with the CTI/playhead?
If it's not this, let me know.
the duration has been set to constant or single frame the entire time with with 0 and 100 at start and end and the playhead over an area where it shows the stroke, so i don't think that's the problem. i use the paint and clone tools all the time, they just stopped working the other day.... any more ideas?
got the brush tips back though (that was simple, just had to restore to defaults)
Sorry, I have no idea as those are the most typical reasons why brush strokes are not visible. There must be some odd Paint setting somewhere.
If you want, create a simple project that shows this problem (just paint a couple of paint strokes on a solid layer, for example) and e-mail it to me: arozenfe(sign)adobe.com < "at" sign changed to avoid spambots.
Got your project.
The reason why you are not seeing your paint strokes, is because the "Flow" parameter in Stroke options is set to 0. If you raise the value, the paint stroke gradually becomes visible.
These things are sticky, so you may have changed it in the Paint panel at some point without realizing it, and it remained like that.