When a player want to spawn a raid base, I have this message:

(18:49:25) | Exception while calling NextTick callback (KeyNotFoundException: The given key 'amount' was not present in the dictionary.)

at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <f98723dd4586469db5213ec59da723ca>:0

at Oxide.Plugins.CopyPaste.PasteEntity (System.Collections.Generic.Dictionary`2[TKey,TValue] data, Oxide.Plugins.CopyPaste+PasteData pasteData, BaseEntity parent) [0x008fb] in <7e7232f912964e78b1cf6e7091e2aa4c>:0

at Oxide.Plugins.CopyPaste.PasteLoop (Oxide.Plugins.CopyPaste+PasteData pasteData) [0x00088] in <7e7232f912964e78b1cf6e7091e2aa4c>:0

at Oxide.Plugins.CopyPaste+<>c__DisplayClass46_0.<PasteLoop>b__0 () [0x00000] in <7e7232f912964e78b1cf6e7091e2aa4c>:0

at Oxide.Core.OxideMod.OnFrame (System.Single delta) [0x00051] in <beb2b64691c64e2b95b99491bd85442c>:0

Nearly the same here:

If i paste a building it only spawns half, and if i try undo it, it says that i first have to paste something and doesn´t undo it.

I'd bet that it has to do with the new wallpapers.  The copied base file should be in the copy/paste plugin data folder.  

Try searching "wallpaper" and then change all the health numbers to 9999.