Error in Console When Claiming Rewards

Players frequently are unable to claim their rewards with /vote or /claim. When they attempt to do so, there is an error in console:

Web request callback raised an exception in 'RustServer.gg Vote v1.2.1 by NightHawk@Codefling' plugin [200] (Object reference not set to an instance of an object)
   at void Oxide.Plugins.RSVote.GiveRandomReward(BasePlayer player) in /home/container/carbon/plugins/RSVote.cs:line 147
   at void Oxide.Plugins.RSVote.HandleResponse(string url, int code, string response, string action, BasePlayer player) in /home/container/carbon/plugins/RSVote.cs:line 106
   at void Oxide.Plugins.RSVote.Execute(string url, string action, BasePlayer player)+(int i, string s) => { } in /home/container/carbon/plugins/RSVote.cs:line 84
   at void Oxide.Core.Libraries.WebRequests+WebRequest.OnComplete() in /home/runner/work/Carbon/Carbon/Carbon.Core/Carbon.Components/Carbon.Common/src/Oxide/Libraries/WebRequest.cs:line 385

Usually it works if they try again a few minutes later.