Im making this post to hopefully help anyone that runs into the same absurd issues i have the past few weeks. i will try to recall and explain everything that happened and the steps i took to solve it.
1. The issue at hand:
starting seemingly randomly. i had just reinstalled windows due to a corruption unrelated. so it was a fresh installation of windows 10. one of the first games i reinstalled was R6S and it worked fine initially. randomly the game started going to background processes when i would exit. id then have to manually close the process in task manager to close R6. other than that everything worked fine one day. and then the next day when i tried to play some more. the game wouldnt connect to online services with the battle eye error code of [0-0x00001001].
2. steps taken:
after i started getting the error about battle eye i found online someone suggesting to try different settings for the battleyee service. so i tried auto start, delayed start, manual start. nothing change except steam started giving me the error of "Tom Clancy's Rainbow Six Siege is attempting to launch with the optional parameters shown below. "-uplay_steam_mode /belaunch -be"" and i could click through it but then the game wouldn't launch at all and would just go to background processes. so the second thing i tried was adding uplay as a "game" on steam and launching uplay from steam, then R6 from that uplay. it made the game actually able to launch but the same battle eye error would occur for online play. i then started trying everything i knew for troubleshooting which included, complete re-installation of the game, of uplay launcher, verifying cache etc. nothing did anything at all.
3. Support:
after having contacted support they ran me through the normal troubleshooting which i mostly had exhausted so then moved onto other things i hadn't. most of which include, disabling all startup programs, running game as admin, checking if i had any network issues with the launcher, that i had the right direct X libraries, restarting battle eye service after launch, updating/ reinstalling battle eye, uninstalling everything and reinstalling again, restoring windows to a previous version where the game worked, checking proxy, trying uplay offline mode, port forwarding, disabling firewall, flushed my DNS, reset hosts file, flush config steam files, clean installation of my graphic drivers, completely different drivers (windows vs nvidia ones) etc etc.
4. Solution:
i then get an update today on my ubisoft case. i dont expect any useful new information having tried everything multiple times. i check and there was a suggestion to try running a command to check for corrupt files in windows. the command is "sfc /scannow". i opened an admin cmd terminal. ran the command. it came up with dialogue saying it fixed corrupted files. i tried to open R6. nothing new. welp. i then decided to verify the cache in steam since thats what i do after pretty much every attempt so far. it finished verifying. i hit play. and boom. absolutely no issues now. everything runs as normal. WOW. what an adventure. so i just hope that if someone ever runs into similar issues they stumble across this post and i can help in any way possible. cant believe it was just one command in a terminal to fix this whole nightmare.