Running TcmTemplateSync.exe with the --extensions parameter but wihtout values for that parameter will crash the application. To reproduce run: TcmTemplateSync.exe --extensions Error: Unhandled Exception: System.NullReferenceException: Object reference not set to an instance of an object. at Tridion.Extensions.Deployment.TemplateUpload.Program.<>c__DisplayClassa.<M ain>b__4(String v) at Mono.Options.Option.Invoke(OptionContext c) at Mono.Options.OptionSet.ParseValue(String option, OptionContext c) at Mono.Options.OptionSet.Parse(String argument, OptionContext c) at Mono.Options.OptionSet.Parse(IEnumerable`1 arguments) at Tridion.Extensions.Deployment.TemplateUpload.Program.Main(String[] args) Tested with https://github.com/willprice76/templating-dev-tools/blob/c736e772fe457f57108ef8ad413957b0d281b369/TcmTemplateSync/release/1.0/TcmTemplateSync.exe Probably simple to fix, low prio so I am not going to fix it right away.