An internal server error is a fatal error from the page you were trying to access.
If you’re accessing a CGI script (PERL/Python/etc), please check that the script is executable (you can chmod +x the file using your favorite FTP client), and that the path to the interpreter is correct.
for PERL, it’s:
/usr/bin/perl
for Python it’s:
/usr/local/bin/python
The error can also be caused by syntax or compilation errors in your script; please make sure your script compiles and runs before trying to execute it on the Mr.Host servers.