Unable to delete uniqueid strings which has special characters.

[SathishKumar S]

When i tried to delete records by ids, some of the ids has special characters and those are not get deleted. 

var solr = ServiceLocator.Current.GetInstance<ISolrOperations<Users>>();

List<string> ids = usersList.Select(t => t.UserName).ToList();

solr.Delete(ids);

solr.Commit();

The name without special characters are getting deleted and some name with only lower case (small characters) are not getting deleted.

What am i missing?