Do you use any ad blockers? ---- The nsI prefix is used more in coding add-ons than in coding web pages. A standard diagnostic for possible add-on issues is to try Firefox's Safe Mode. First, I recommend backing up your Firefox settings in case something goes wrong. See [[Backing up your information]]. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.) Next, restart Firefox in Firefox's Safe Mode ([[Safe Mode]]) using Help > Restart with Add-ons Disabled In the Safe Mode dialog, do not check any boxes, just click "Continue in Safe Mode." Any luck? ---- If that doesn't help, when you have a problem with one particular site or platform, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site. 1. Clear Firefox's Cache orange Firefox button ''or'' Tools menu > Options > Advanced On the Network mini-tab > Offline Storage : "Clear Now" 2. If needed, delete each site's cookies here While viewing a page on the site, right-click and choose View Page Info > Security > "View Cookies" (You either can do this as you visit each problem site, or change the domain listed in the search box at the top of the dialog.) Then try reloading your blog(s). Does that help?