ArgumentOutOfRangeException #1
Description
An unhandled exception of type 'System.ArgumentOutOfRangeException' occurred in System.Private.CoreLib.dll: 'Non-negative number required.'
in the line (355)
var list = new List<KeyValuePair<string, string>>(tagSet.Count - tagsEntered.Count);
(tagSet.Count - tagsEntered.Count) will always return a negative number if there are more tags in the main set than in the ammended set.
Considering the comment says looking for the 'remaining tags' suggest just using (tagSet.Count) as there can never be more 'remaining' that there were to begin with.