error CS0104: 'Hashtable' is an ambiguous reference between 'ExitGames.Client.Photon.Hashtable' and 'System.Collections.Hashtable'

error CS0104: 'Hashtable' is an ambiguous reference between 'ExitGames.Client.Photon.Hashtable' and 'System.Collections.Hashtable'

It was a super easy. Currently on line 17 in LoadbalancingPeer.cs there is a bunch of unity versions like:
#if UNITY_4_0 || UNITY_4_1 || UNITY_4_2 || UNITY_4_3 || UNITY_4_4 etc...

All you need to do is add UNITY_2018 to the end and that solve the error.

Adding 2018 can solve you issue.

Please comment if you are having other errors too.

See also: Free Unity Game Assets -The 54 Best Websites To Download