issueTracking key and mds file Git conflict

Since that's the definition of a key field, yes, it needs to be unique. 

Resolve it like you would any other conflict - look at what is changing and figure out which one to keep.  Also take a look at why it's changing so often. 

Hi,

In addition to the reply by Marsha_R, this thread might appear to be useful: https://community.smartbear.com/t5/TestComplete-General-Discussions/Managing-Test-Complete-project-in-GIT/td-p/136956