fixup! Fixed: Skip invalid series paths during validation

src/NzbDrone.Core/Validation/Paths/RootFolderValidator.cs

@@ -1,4 +1,5 @@
-using FluentValidation.Validators;
+using FluentValidation.Validators;
+using NzbDrone.Common.Disk;
 using NzbDrone.Common.Extensions;
 using NzbDrone.Core.RootFolders;
 
@@ -24,7 +25,7 @@ namespace NzbDrone.Core.Validation.Paths
 
             context.MessageFormatter.AppendArgument("path", context.PropertyValue.ToString());
 
-            return !_rootFolderService.All().Exists(r => r.Path.PathEquals(context.PropertyValue.ToString()));
+            return !_rootFolderService.All().Exists(r => r.Path.IsPathValid(PathValidationType.CurrentOs) && r.Path.PathEquals(context.PropertyValue.ToString()));
         }
     }
 }