Community
J,
I've built a VLX with well over a hundred files before so your 53 shouldn't be a problem. Is it just .lsp files your compiling? You should have a bunch of .fas files left over - try loading a couple to see if they work on their own. Try compiling only 01.lsp to 10.lsp, then 10.lsp to 20.lsp, etc. to try to locate any dodgy file.
S