object reference not set to an instance

Anonymous ok so how this issue was resolved for me was by uninstalling Power BI desktop from my system and clearing all cache, cookies and restarting my system. During the uninstalling process what I found was somehow there were two versions of Power BI installed in my windows system. Once through the app store and one through the Power BI website downloads page. I would recommend uninstalling all versions and download the september vr of Power BI. I am using the sep vr, this error has not come back. Hope it helps. You can find previous vrs here https://docs.microsoft.com/en-us/power-bi/fundamentals/desktop-latest-update-archive?tabs=powerbi-desktop

hope this helps! Good luck!