Are you trying to open a project with the xml extension in BAS? Probably your project is damaged, you did not edit it manually using text editors? Try to restore it from backups located here:
C:\Users\User\AppData\Roaming\BrowserAutomationStudio\projectbackups
If you want the second folder to stay updated with the potential changes that appear in the original folder after working with it, then yes, you would need to copy it again.
Are you using any proxies or fingerprints? Have you tried
reloading the page or using different proxy/fingerprint?
Have you tried loading in regular browsers - chrome/ffox etc?
Can you send test script that reproduces that error or just
post exact web link/address?
If your cookies in same format as BAS, you just read it from file to variable and go Network-load cookies-set cookies for browser. If format of your cookies not compatible with BAS, compare and convert all your cookies in right format
