We understand your situation. This is likely caused by some adware that is installed in your PC. You can follow the following steps to recover from this situation. (Hope you are using a windows PC!) First: 1. Go to your control panel->Programs and feature. 2. Search for any programs that is not familiar and not relevant to your PC. The name of the program may be the same as the one in the link you have provided above. 3.Uninstall it and try setting your homepage once again.

Second: If the above steps doesn't help, then it should be because of some adware that is attached or installed on your PC. Follow the steps below: 1. Go to the link https://www.malwarebytes.com/adwcleaner/ 2. Download the free tool, and install it. 3. Run a scan and clean any adwares installed. 4. Restart the PC and now Hit ALT button, navigate to help->Troubleshooting. 5. Click on refresh Firefox This will revert Firefox to factory or default settings.

Hope this helps!

Have a Mac AirBook running OS 10.11.6. Firefox is v 51.0.1 I do have malwarebytes for Mac and have run it and it comes up clean. Also have Norton and it is running on Firefox

BUT just now figured out how to fix it--reverted to "original settings" and started over and now it seems fine!

Thanks again.

I am extremely sorry that I could not help with Mac, I do not have exposure to Mac OS and that is the reason my answer was based on windows. Hope somewhere something that I replied helped you. Thank you!

No worries. I figured out. As mentioned above, by just resetting to original configuration and starting over. Seems fine now.