Sometimes after changing different settings in your admin panel you may see that your website is working properly in all modern browsers except Internet Explorer.
1) To resolve this issue, please, go to Preferences > Perfomance in your Prestashop admin panel.
2) Find the block called CCC (Combine, Compress and Cache). You need to match the second value near each point (Keep everything as original) and save changes.
3) Clear your browser’s cache in IE and check your website. It will work fine after that.
Feel free to check the detailed video tutorial below:
PrestaShop troubleshooter. Website is messed up in Internet Explorer browser