What error are you getting? What are the file permissions now (give "ls -l" and "stat" output).

You've mentioned two completely different errors so far:

• "permission denied" (which I think you got because the file did not have the execute bit set; the permissions were probably 644 (-rw-r--r--).
• "no such file or directory" (which sounds like you removed or renamed the file).

You could also use diagnostics which will give a more verbose error message.