The EA AntiCheat program has over 1,000 error codes. Even major search engines and EA do not publish these lists. The error code you are facing is likely a result of the AntiCheat program reacting to a syntax similar to that of the Windows security system. Assuming you are using Windows 11, I will offer my opinion considering the time that has passed since the mid-April Windows update.
Many gamers encounter AntiCheat errors and attempt to find a solution by reinstalling EAAntiCheat, verifying the integrity of game files, performing a clean installation of GPU drivers, troubleshooting Secure Boot, updating the BIOS and so on.
However, it seems that few people completely uninstall the Battlefield 6 application package and EA applications, and then check the integrity of the volume before reinstalling the EAappInstaller and the Battlefield 6 application package. I didn't want to do it because it takes a long time, but I have solved two unknown errors with this method.
By the way, someone who experienced a similar error, "%4294901855," solved it by reinstalling the Battlefield 6 game in the fall of 2025.
[UPDATE - 04MAY26]
"ouldnnrv24na", please check whether the Windows Event Viewer contains any similar errors, or errors that corroborate the '%%4294901858' EAAntiCheat error, during the time period when the error occurred. In particular, if there are any entries in the 'Application', 'System' or 'Security' logs, please review those logs and their details. If such entries exist but you are unsure what they mean, could you please post them here? Depending on the log entries, it may be preferable to try an alternative method before resorting to the time-consuming approach mentioned earlier.
