avonbanya For the blank screen, please clear Edge's Internet Explorer-mode data. How to do so is covered at the end of this article:
https://support.microsoft.com/en-us/microsoft-edge/view-and-delete-browser-history-in-microsoft-edge-00cf7943-a9e1-975a-a33d-ac10ce454ca4
For the rest, please try installing your content into a clean user folder. Here's how:
[Read First] Sims 3 Store guide | EA Forums - 11157679
The instructions also cover how to move your saves and other content from the old Sims 3 folder to the new one so you don't lose your saves or anything else you care about.