User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170824053622 Steps to reproduce: Add/modify rules in AdBlockPlus Actual results: FF actively does something with memory/CPU as indicated by Task manager as a results it hangs (title bar says "Not responding") for few seconds (5..10). Expected results: FF should continue working smoothly. As far as I read in ABP site this is caused by some new memory management (in preparation to 57 release?) and is the issue of FF, not ABP. Whatever. Please, fix ASAP.

(In reply to Ed from comment #0) > As far as I read in ABP site this is caused by some new memory management > (in preparation to 57 release?) and is the issue of FF, not ABP. Source?

(In reply to Kohei Yoshino [:kohei] from comment #1) > (In reply to Ed from comment #0) > > As far as I read in ABP site this is caused by some new memory management > > (in preparation to 57 release?) and is the issue of FF, not ABP. > > Source? And your ABP version is ...?

Hi Again! Kohei, I am not sure where I saw it sorry. ABP v.2.9.1 Element Hiding Helper for ABP v.1.4 The problem appeared recently, more or less after all add-ons where marked as "Legacy" in FF (or a little bit later).