Fixed #1547

src/Ombi/Startup.cs

@@ -1,8 +1,10 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Net;
 using System.Security.Principal;
+using System.Threading.Tasks;
 using AutoMapper;
 using AutoMapper.EquivalencyExpression;
 using Hangfire;
@@ -103,8 +105,7 @@ namespace Ombi
                 options.Password.RequireLowercase = false;
                 options.Password.RequireNonAlphanumeric = false;
                 options.Password.RequireUppercase = false;
-                options.User.AllowedUserNameCharacters =
-                    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 -._@+";
+                options.User.AllowedUserNameCharacters =string.Empty;
             });
             
             services.AddMemoryCache();