Issue:
After importing JSON of successful recording in Selenium builder, the test case execution fails on first step: GET.
It just opens Firefox browser and doesn't instrument it.
Environment:
It happen with Mozilla FireFox version 45 and above.
Cause:
It is due the fact that FireFox version 45 and above needs Selenium builder updated libraries of version 2.53 and above.
Resolution:
1. Replace the current Selenium JARs you have under <DevTest_Home>/lib/shared/ folder with JARs from version 2.53.
2. They can be downloaded from - http://www.seleniumhq.org/download/
3. Go to section Selenium Client & WebDriver Language Bindings.
Download from here:
Language Client Version Release Date
Java 2.53.0 2016-03-15