Error For input string: "Green" Board configuration Card colors error

Question

All of a sudden started getting this error on our JIRA Board

Error

For input string: "Green"

Upon investigation the error only appears when selecting "Priorities" in the Board Configuration–>Card Colors–>Color Based on–> Priorities

How can I eliminate this error, while still using Priorities as a Card Color.

James Tention1 · Answer

Any help on this. The Card colors are unusable when selecting Priorities for Cards. Is it a problem with the installation or a server side admin tweak?

Jesse Bickel · Answer

More info on the installation (unsure how much is relevant):
Version 6.4.2
Database type oracle10g
Operating System Linux 2.6.32-504.16.2.el6.x86_64
Clustering OFF
JIRA Agile - 6.7.0
(Other plugins: Structure - 2.10.3)

Custom Fields 61
Screen Schemes 53