The cause of this is because the file path name is too long for Windows to read (Windows has a character limit of 256 characters)
The best fix for this is to relocate your package folders to a location that is easier to find, a shorter path and updated usercfg.opt to match
•Locate your current Official and Community folders (FindPkgsTest will give the current location)
•Copy and paste both folders to a new prepared location (for example D:\MSFS\Packages) either on the same drive or if you prefer on a different one
•When copying you may see a warning that the new location does not support encryption but you will still be able to “copy without encryption” and that is what you want to do
•Note this will take a while as there is about 120GB to copy. You will also need enough free space on the drive to hold the files so if it is the same drive then you will temporarily need enough space for 2 full sets of files.
•Once copied locate and open your usercfg.opt file in notepad (FindPkgsTest – we can send you a download link to this file - will locate it and let you click a button to open it for editing)
•At the end of the file there will be an InstalledPackagesPath entry showing the current location in quotes. Edit the path in the quotes to match the new location (in the example above this will be to “D:\MSFS\Packages”)
•Close and save the file
•Run the product (Product Name) installer and install it. It should now work without any problems
•Start up MSFS and check it loads without trying to update anything
•Check the product (Product Name) appears in the aircraft choices
•If all this is working without problems then you can go back to your original Official and Community folders and delete them to free up the old space again
If you prefer the other way, then you’re welcome to uninstall MSFS then reinstall it again but this time when the updating/downloading screen first appears use the “Browse” button to select a custom (easier to find and short path) location on the drive you want the bulk of the game to go to. This may be a last resort but if you decide you are going to reinstall anyway because of multiple problems this would be your chance to set things up in a much better manor to easily locate the files