fivem errors out every time it tries to update

Run it as admin once and see if the update goes through, that fixes a surprising number of these. If not, clear the cache: right click the FiveM shortcut, open file location, go into the data folder and delete everything in there except game-storage. Then add the whole FiveM folder as an exclusion in your antivirus, Defender likes to quarantine files mid-update. What does the error actually say? A failed download and a crash right after updating are different fixes. If it's a download error every single time, it's often the connection rather than FiveM. Some ISPs and a lot of VPNs block the servers it updates from, so try with the VPN off, or on a phone hotspot for one run, just to rule that out.