server files have not been downloaded properly

when i try to download my server theres an error message that says [UPDATER] Starting server update.

[UPDATER] Server branch: live.





[UPDATER] Updating server from steam.



[UPDATER] ****************************

[UPDATER] ERROR: Failed server update.

[UPDATER] ****************************



[UPDATER] ***********************************************************

[UPDATER] ERROR: Mods were not processed as server update had errors.

[UPDATER] ***********************************************************



[UPDATER] Finished upgrade process.

and when i validate my files it says i have not dowloaded the server files properly, any fix ?