Since the merge of the two modules 'web' from enterprise and community it was impossible to scroll in the side menu and in the main content of a community database from Internet Explorer 10 & 11 but it is working in Edge. This was due to missing css 'height' attribute on the '.o_main' class that should be set to 100% for IE to let the flex elements know the size of their parent. This was introduced in rev https://github.com/odoo/odoo/commit/977db823c