Sage 300 CRE - COST CODE ISSUE/ERROR - Cost Code Not Allowed to be set up or used for a project.

I have 2 Cost Codes that have randomly stopped working for 2 users. I am the Admin and it won't let me use them for 1 specific job only. The other 2 users is for any project.  

Won't allow them to be used when entering a Change Order Request in Project Management, nor when entering an invoice in Accounts Payable. The 2 codes are also missing from reports.

It says the Cost Code doesn't exist for that project, but won't allow us to add it. Support seams stumped. We've been using these cost codes for Years!!!

This happened last month to a user with a different cost code and a new user had to be created. Now a month later it's happening again but with 2 users and now myself that is the Admin for Sage.  

Has this happened to anyone else and any possible ideas for solution? We already rebooted our PC's and server.