Issues with Logging in Site using IE

Hello, my site is no longer working properly on Internet Explorer. My users can get to site homepage and type in login information, but the page does not then proceed to search page properly. (All other browsers are just fine.) I have not updated anything on my page since this has changed, and after speaking with several of the users there hasn't been any changes with their browser version since it has stopped working properly.

I have worked with my webhost and we performed all of the troubleshooting we could think of, so it was determined that it must be on coding side. Has this happened to anyone else, or do you happen to have any idea of what may be causing this type of issue? I need to get this back to working immediately, as the majority of my users are required to use IE only. Thanks for any help in advance!