Appears in Resilio Active Everywhere v4.1 together with File Locking functionality.
The error appears on the jobs with File locking enabled, if the file was opened on multiple devices at the same time, but within the lock propagation timeframe.
Locked files information is distributed across other Agents in the job via the Lock server. On average it may take around 4 seconds. If a file is opened on multiple devices within this period, only one of the nodes will impose the lock and be the lock owner - the first one that reaches the lock server.
Other nodes will report the error. Compare the Agent reporting the error and "User name, Lock owner" on the two screens.
To fix the error, close the file on other nodes without changes and wait till the file is unlocked on the lock owner.
Error code SE_FS_SHARED_LOCK_REJECTED_DUE_ACCESS_RACE