Crash After seamless travel

I create server and my clients connect to it (like lobby map) then i use seamless travel for my game map with same GameMode. So its works fine, but when match end - server call servertravel again for return to lobby map and now server open map fine, but clients get crash

Assertion failed: 
It.Value().Object.IsValid() || NetGUIDLookup.FindRef(It.Value().Object) == It.Key() || It.Value().ReadOnlyTimestamp != 0 
[File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Engine/Private/PackageMapClient.cpp] [Line: 2303] Failed to validate ObjectLookup map in UPackageMap. 
Object '/Game/Logic/Blueprints/Weapons/Pistol' was not in the NetGUIDLookup map with with value '69'.

So i dont know how to fix it and i need some help with it :slight_smile:

P.S. Crash not only with this object, its difrent each time.