I use Fabric Crashlytics to monitor crashes of our iOS app. On the status view below, there are two version numbers on right side(which I deleted actual numbers by orange color lines).
Ex
1.2.3(2) - 2.0.1
Are what are those numbers and numbers inside parentheses.
If it was one version number I would know it is a version causing the crash but there are two.
That's your app version number and build number. E.g. 1.2.3(2) is version: 1.2.3, build 2.
The range is there to indicate that the crash has happened in multiple versions of your app. So the earliest version (where the crash has been logged) is 1.2.3(2) and the latest version (where the same crash has been logged) is 2.0.1.