The latest Firefox version is no longer compatible with iMacros, you need an older version of Firefox to use imacros.
– Recommended Firefox version – Firefox 47
– Recommended imacros version – iMacors 8.9.7
Common error when not using recommended Firefox and imacros versions-
TypeError: returnNumber is null, line 2 (Error code: -991)
Follow these steps to downgrade:
1. Disable Automatic Firefox Updates
* Note: If you dont have firefox installed yet, do Step 2 first then come back to Step 1.
– Copy and paste this in your firefox browser – about:preferences
– Look for the Firefox updates section
– Make sure you have this option checked – Never check for updates
2. Download and install Firefox 47
3. install Firefox Add-on – iMacros 8.9.7