Cannot Save Menu

I have a site I am developing for a client on my servers at https://www.meleweb.calhans.com. It has a menu with lots of items and subitems which was working fine until just recently. Now all of a sudden I cannot save the menu after making changes. I can add, delete, or modify any of the menu elements, but when I click “Save menu” I am taken to a blue and black page that says “this page is not available. a general error occurred.” I have tried contacting the host and setting parameters to increase my number of menu items. I have tried contacting the theme developer and have changed my folder permissions. I have reset my plugins folder, tried deactivating every plugin with no change. I am ready to pull my hair out. Please help!