Why would not all of my "Fix Release" values not show in JQL dropdown when configuring Kanban Swim Lane?

Question

I have several stories that have a value in the "Fix Release" field of "WFX Mar 2014", but when I go into configure my Kanbanboards swim lanes to configure and I put the JQL filter in to pull those stories 1) It doesn't show that value at all as I start to type and 2) it gives me an error of "The option 'WFX Mar 2014' for field 'Fix Release' does not exist.

Jira 6.0.4             Jira Agile:  v6.3.5

JanaW · Accepted Answer

Problem Solved: Although we couldn't see it in the Fix Version, ther were a couple of spaces where there shouldn't of been in the Fix Version. We found it only because we were using Project Configurator and it showed a discrepency between our Dev environment and Production for that field value, which made us take a closer look and found the spaces.