You have always been working on APROPLAN on Internet Explorer and it suddenly stops working.
Internet Explorer is blocking APROPLAN, for instance after editing the name of a document.
The solution is the following: add https://app.aproplan.com to the list of Internet Explorer's trusted websites.
To do this, please follow these quick steps:
1) Click on the top right corner on the settings icon
2) Click then on "Internet options" in the menu
3) A windows opens, please click on "Privacy"
4) Go in the settings next to "Turn on Pop-up Blocker"
5) Please add APROPLAN's URL (https://app.aproplan.com) and click on "Add"