The error is from Rust, not Oxide. They are aware of it and are working on a fix.

no. look at changelog and you see problem with NPC. 

Nothing related to NPCs in the changelog, it hasn't been formatted yet.

This issue is from Rust related to oil rigs, not Oxide.

OT but a few users on Reddit reporting object thrown on ground are clipping right through. Hope they catch that and stuff it into the fix.

Have did that once already (delete steamapps folder, then downloading update again), Server is booting after that, however without plugins.

If you are not receiving this error, please create a separate thread.

Sorry, it's not a UMOD issue, tossed it out there in hopes a dev who hangs here may see it. (Note I am receiving the same error mentioned in thread title, not that it matters.)

Install umod after every update 

Did that also... 

You'll need to wait for a Rust update to fix the issue, else change to a map with an oil rig I believe.

Using stream "3" now, when the server were up without Oxide,a oil rig were present.

The same issue, only on all barren servers. With Procedural map all good.

[2019-03-08T03:29:14] 99%
[2019-03-08T03:29:14] 100%
[2019-03-08T03:29:14] Monument Navmesh Build took 44.49 seconds
[2019-03-08T03:29:15] ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
[2019-03-08T03:29:15] Parameter name: index
[2019-03-08T03:29:15] at System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) [0x00029] in <ac823e2bb42b41bda67924a45a0173c3>:0
[2019-03-08T03:29:15] at System.ThrowHelper.ThrowArgumentOutOfRangeException () [0x00000] in <ac823e2bb42b41bda67924a45a0173c3>:0
[2019-03-08T03:29:15] at AIInformationZone.GetForPoint (UnityEngine.Vector3 point, BaseEntity from) [0x0004d] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at Door.ServerInit () [0x001b5] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at BaseNetworkable.Spawn () [0x00035] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at BaseEntity.Spawn () [0x00000] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at BaseEntity.SpawnAsMapEntity () [0x00068] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at ServerMgr.SpawnMapEntities () [0x00038] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at ServerMgr.Initialize (System.Boolean loadSave, System.String saveFile, System.Boolean allowOutOfDateSaves, System.Boolean skipInitialSpawn) [0x0001d] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at Bootstrap+<StartServer>d__17.MoveNext () [0x001eb] in <60f963ef10394701b14d1e1f5d15459a>:0
[2019-03-08T03:29:15] at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00027] in <a65dafb2dd744420a9e0f3003d14e0b0>:0
[2019-03-08T03:29:15] (Filename: <ac823e2bb42b41bda67924a45a0173c3> Line: 0)​

After this new "Patch fix" still the same error, terrible

If you installed Oxide over it, you downgraded Rust. You'd need to wait for the compatible Oxide build.