I can see that there is an old thread without resolution about this topic, but after the update I got the same issue. Same message 

Whenever I do it I see these outpot on the server console 

(09:41:57) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall/wall.prefab
(09:42:18) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall.frame/wall.frame.prefab
(09:42:19) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall.frame/wall.frame.prefab
(09:42:21) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall/wall.prefab
(09:42:26) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/floor.triangle/floor.triangle.prefab
(09:42:27) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/floor.triangle/floor.triangle.prefab
(09:42:31) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/floor.triangle/floor.triangle.prefab
(09:42:32) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/floor.triangle/floor.triangle.prefab
(09:42:43) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/floor.triangle/floor.triangle.prefab
(09:42:48) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall/wall.prefab
(09:42:49) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall/wall.prefab
(09:42:51) | Converting prefab name to lowercase: Assets/Prefabs/Building Core/wall.frame/wall.frame.prefab
(09:43:08) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:09) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:10) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:11) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:12) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:13) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:19) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:20) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:21) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:28) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:30) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:31) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:32) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:33) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:34) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:35) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:36) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:37) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:38) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:39) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:40) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:41) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:42) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:43) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:44) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:45) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:46) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:47) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:48) | KeyNotFoundException: The given key was not present in the dictionary.
(09:43:49) | Converting prefab name to lowercase: Assets/Prefabs/Building/door.double.hinged/door.double.hinged.toptier.prefab
(09:43:49) | KeyNotFoundException: The given key was not present in the dictionary.

I'm trying to do the normal thing, place a foundation where I placed a TC and then try to remove it, but it doesn't work, always spamming with the same message. 

Let me know if you need more info or I can test something else. I always had the configuration in default just because I don't know what to change 

Found any solution?

Suddenly the error just stopped but I didn't do anything

It is back again, I cannot do anything, I tried changing everything in the configuration even add the building block as a "other assets" but it is not working 

anyone that can guide me on this issue? 

I've had the same issue the past few weeks, and it has not gone away. Users are only able to remove deployed objects.

Also having this same exact issue for the last month. Users can only remove deployable objects.