I have tried everything but the recent update will not install getting stuck decompressing files after downloading. It’s driving me nuts . I have tried deleting the relevant folders and redownloading but it’s failing all the time. I’ve been with MSFS2020 since the beginning with a good spec machine and fast download but this is the worst it’s been! I can’t get the sim back. It’s hideous.
I don’t know if you have seen this checklist.
Its title is not specific to your issue, but it there are suggestions in there that may be of some help.