Ive been using texshop on my mac for a while with no problem at all, i fixed the El Capitan problem by relocating the compiler, but for no apparent reason, by file has stopped typesetting. There is no error showing in the console. When I try and open the pdf file it says its not recognised by preview. Also when I try to compile the file, my mac runs hot and activity monitor says pdftex is running at around 98%. Ive tried uninstalling and reinstalling and i cant seem to figure out how to fix it, any help would be appreciated.
Apparently version 3.51 of TeXShop has some problems in El Capitan, but updating fixes everything.
It is always a good idea to update before asking for help with a problem. Especially considered as another question here was closed as off-topic because the issue was fixed by an update. Not sure this is a duplicate of that one, but surely the same argument for the closure of that one applies here.
To know more about this, e.g. where this problem comes from, one can ask the programmers behind TeXShop, or try their luck wading through the source which can be obtained here, and seeing if they can find the problem's source out by themselves.
A good way to ask questions of this sort is to post a message on the MacTeX mailing list tug.org/mailman/listinfo/mactex. Dick Koch, the developer of TeXShop is active on that list.