If you locate the corrupted media, I have found that the issue tends to be a corrupt “clip” in FCP. Not necessarily the actual media. So be for you try and recreate the media from tape, or wherever it came from, try reimporting, reconnecting won’t fix it because the actual FCP “clip/pointer/alias” is broken, and over cut it.
Also, as far as locating the bad frame… If you know about what % it consistently crashes at, then you can change the TC display to be frames (right click a TC field in Canvas, select frames) and you can get a pretty good approximation by figuring the percentage of the frame count.
Another thing to look for, if you have stills in you timeline, any still that is larger than 3.5k in either direction will usually cause FCP to crap out.