Cant open app in browser

Dear Mendix, For my project I have to use the (old) 4.5.2 modeler. I always used on of the latest versions but for my school I had to downgrade it to 4.5.2. The only problem is that when I run the project and then try to open it in my webbrower, it will be loading endlessly. Nothing goes wrong when running the project, and nothing happens when I open it in my browser, but it just won't stop loading. Does anybody has an idea how I can fix this problem? I have never had this problem before. PS: I did not convert my project to this older versions, I made a new project in this version so that can't be the problem. Thank you
1 answers

delete default database under project settings, run the project again and it should create a new one. I faced this type of problem whenever i uploaded a file using the System.FileDocument generalization, and the web browser would only stop loading once i deleted that file again.