Adblock Plus 2.9.1 for Firefox released · 2017-06-07 20:11 by Wladimir Palant
Unfortunately, the Adblock Plus 2.9 release didn’t go as smoothly as we hoped for. Most importantly, the performance degradation caused by the new data storage turned out more severe than we expected, some users were experiencing regular noticeable browser hangs. While the performance of reading and saving Adblock Plus filters hasn’t improved yet, we turned off filter hit counts by default in Adblock Plus 2.9.1 as a first consequence to make sure the data no longer needs to be saved that often (issue 5298). Users who need this functionality can turn it back on by clicking the ABP icon, going into “Options” and checking “Count filter hits.” We will be looking into other ways to improve this, even though the main issue can only be resolved by the Firefox developers.
It also wasn’t noticed before release that the new data storage doesn’t work in Thunderbird and SeaMonkey, so these users ended up with filters being reset on each restart. This has also been resolved in Adblock Plus 2.9.1 (issue 5279, issue 5285), the original data should show up again now. Some users are reporting similar issues in Firefox, a problem we couldn’t reproduce so far. If you are experiencing data loss on Firefox and are willing to let me debug the issue on your computer (via TeamViewer or a similar desktop sharing tool), please let me know in the comments below.