When there is an empty tag in the system this line throws a java.lang.StringIndexOutOfBoundsException: String index out of range: 0:

https://opensource.ncsa.illinois.edu/bitbucket/projects/CATS/repos/clowder/browse/app/controllers/Tags.scala?at=refs%2Fheads%2Fmaster#143

Was able to add empty tags from GUI by typing "tag, ". This adds two tags, one of which is empty. Need to check both GUI logic as well as API endpoint