I didn't know there was a WIPR 1, 2 and 3. I just have one of them. That's scary and frustrating that it could be one of my apps, and there is no way to tell. In doing a Google search just now, I guess I'm not the only one, though I didn't find a solution.
🤦🏻♂️ I just remembered you running Sierra (MacOS 10.12). I forget whether it was in High Sierra or Mojave, Apple dropped support for the style of extensions used in previous MacOS and Safari versions and switched to extensions downloaded from the App Store. That is when WIPR 1, WIPR 2, and WIPR 3 came on the scene. As to AdBlock, as far as I know AdBlock Pro - Legacy
($9.99) is the only supported
version of AdBlock for legacy systems such as Sierra. While your legacy ad blockers may continue to work, they will become less and less effective as advertisers develop newer ways of avoiding blockers. I suggest you consider Uninstalling all
of your current ad blockers and install AdBlock Pro - Legacy
Unfortunately, while that will most likely improve your ad blocking, it does not solve either the issue of being unable to reach FineTunedMac using Safari or Safari's disappearing tabs. While I can think of any number of reasons, you might be getting that error message, all of them would affect any browser on your system, not just Safari. The one thing I can think of would be an intermittent network situation that coincidentally occurred while you were using Safari. (Yes, I know that is thin and still leaves the disappearing tabs completely unexplained, but it is all I've got at the moment 🤓.)