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
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?
