Suddenly missing Module, not showing up

[ojars]

Hi! I'm running into problems with my page. It has problems with module positions. It works well if I fill it with menu module located in "izvele" position. However, I'm using my own HTML menu, which is running with FLEXI CUSTOM CODE. But the strange thing is that - the module doesn't show up. It's enabled, its in the index.php, template css and in the template file. However, after switching another module in a different place, it just suddenly was missing. I was running the page for about 3 months without problems, when suddenly this mistake appeared and the module was missing. I think It's the Joomlas bug, because I can't upload any files to page, but Host says that everything should be OK. I'm running 3 joomla pages on one host, I haven't touch 2 of them for years, both of them have the same template, but also have the same problem, doesn't matter that I havent even touched the admin panel. Strange thing, isn't it? Could you help me?

PS. The position is showing Menu type of module, but flexi custom code not.

[Per Yngve Berg]

Validate your html code. There is start/end tag mismatches.

http://validator.w3.org

[ojars]

Found the solution!

The problem was not in the code, but in the module settings. I didn't switch off "PHP script". Now everything is working fine.