prefs.js is where almost all settings are stored.

AFAIK & can tell from reading, only the currently installed persona is stored in prefs.js. That's all I saw when looking in the file. Could be wrong.

I'm thinking the names / URLs of the others that have been installed at one time, are held in another location.

Also, at least for the currently installed persona, Fx / TB checks w/ Mozilla servers 1x / day to see if there are "updates." Since the files of non-active personas are re-downloaded, each time you enable them, I don't see why Mozilla would check for updates on inactive ones (they may not). Dunno.

But, I have disabled themes, plugins, etc., that it continually notifies of updates. But, those have actual files stored locally.

I have only one disabled persona.

This is what is in my prefs.js lightweightThemes.usedThemes;[{"id":"328285","name":"fractal summer colors","headerURL":"https://addons.cdn.mozilla.net/_files/328285/fractalsummercolorsalto.jpg?1386612925","footerURL":"https://addons.cdn.mozilla.net/_files/328285/fractalsummercolorsbasso.jpg?1386612925","textcolor":"#ffffff","accentcolor":"#000000","iconURL":"https://addons.cdn.mozilla.net/_files/328285/preview_small.jpg?1386612925","previewURL":"https://addons.cdn.mozilla.net/_files/328285/preview.jpg?1386612925","author":"candelora","description":"✿Theme Designed by candelora ©✿\n\nCopyright fractal image base by SuicideBySafetyPin on deviantART link: \n<a href=\"http://outgoing.mozilla.org/v1/64c04dbb3f247f24bd6d8cd035e74518537949c422bfb0ef34e61030fb12e878/http%3A//suicidebysafetypin.deviantart.com/art/Summer-Colors-217073954\" rel=\"nofollow\">http://suicidebysafetypin.deviantart.com/art/Summer-Colors-217073954</a>\n\nTAGS:\ncurls,circles,wheels,smooth,purple,pink,violet,cyan,yellow,\nturquoise,red,blue,shine,light,rainbow,colorful,fantasy,\npsychedelic,magic,candelora,firefox","updateURL":"https://versioncheck.addons.mozilla.org/en-US/themes/update-check/328285","version":"1.0","updateDate":1404261386425,"installDate":1404261386425}]

I added another and ow have lightweightThemes.usedThemes;[{"id":"286995","name":"Fresh Green Leaves","headerURL":"https://addons.cdn.mozilla.net/_files/286995/Header.jpg?1298888549","footerURL":"https://addons.cdn.mozilla.net/_files/286995/Footer.jpg?1298888549","textcolor":"#000000","accentcolor":"#fcfcfc","iconURL":"https://addons.cdn.mozilla.net/_files/286995/preview_small.jpg?1298888549","previewURL":"https://addons.cdn.mozilla.net/_files/286995/preview.jpg?1298888549","author":"Sinine","updateURL":"https://versioncheck.addons.mozilla.org/en-US/themes/update-check/286995","version":"1.0","updateDate":1404362440153,"installDate":1404362440153},{"id":"328285","name":"fractal summer colors","headerURL":"https://addons.cdn.mozilla.net/_files/328285/fractalsummercolorsalto.jpg?1386612925","footerURL":"https://addons.cdn.mozilla.net/_files/328285/fractalsummercolorsbasso.jpg?1386612925","textcolor":"#ffffff","accentcolor":"#000000","iconURL":"https://addons.cdn.mozilla.net/_files/328285/preview_small.jpg?1386612925","previewURL":"https://addons.cdn.mozilla.net/_files/328285/preview.jpg?1386612925","author":"candelora","description":"✿Theme Designed by candelora ©✿\n\nCopyright fractal image base by SuicideBySafetyPin on deviantART link: \n<a href=\"http://outgoing.mozilla.org/v1/64c04dbb3f247f24bd6d8cd035e74518537949c422bfb0ef34e61030fb12e878/http%3A//suicidebysafetypin.deviantart.com/art/Summer-Colors-217073954\" rel=\"nofollow\">http://suicidebysafetypin.deviantart.com/art/Summer-Colors-217073954</a>\n\nTAGS:\ncurls,circles,wheels,smooth,purple,pink,violet,cyan,yellow,\nturquoise,red,blue,shine,light,rainbow,colorful,fantasy,\npsychedelic,magic,candelora,firefox","updateURL":"https://versioncheck.addons.mozilla.org/en-US/themes/update-check/328285","version":"1.0","updateDate":1404261386425,"installDate":1404261386425}]

That is confusing looking enough, but what it demonstrates is it is a list of personas with each enclosed in {} brackets.

So the information is stored in the preference lightweightThemes.usedThemes in prefs.js.

Thanks Matt. I must have been looking in the wrong prefs.js file (from another profile). I see those entries now, but...

Not all of them appear under my Addon Mgr. No big deal, except in TB, I continue having random problems previewing or installing personas on AMO.

Any suggestions to "clean up" prefs.js - other than deleting all entries for personas? So maybe the personas problem goes away, but I don't have to RE-create all of my email accts (quite a few).

Or a tool to import JUST the actual email acct settings out of prefs.js, but not most other entries in the old prefs.js? This personas issue persists, when I BU / import bare bones data from the old profile. Of course, that includes email acct settings (in prefs.js). For stored email, I can just copy over the Mail folder.

I'm guessing corruption in prefs.js is causing the problem, as not too much else is being imported from old profile that likely affects personas.

I'm comfortable manually editing *.js, *.sqlite or most profile files. Sometimes manually editing is slower than starting over, but maybe not when there's a dozen accounts.

When I start TB w/ a temp profile (safe mode), the personas problem goes away. The prefs.js that TB creates in that temp profile is almost empty.

In the (latest) new profile that contains acct settings (thus the old prefs.js), I did switch between the couple of remaining persona names showing in Addon Mgr > Appearance, then found installing personas no longer worked.

What exactly is the problem?

reset the lightweightThemes.usedThemes in your backup profile and see if that fixes the issue.

right click lightweightThemes.usedThemes and copy and paste into notepad and save the file (how large is it)

I see a couple of possible issues, not the least is with long strings the allocated length can easily be exceeded.

The brackets have somehow been messed up and the entry it corrupt. (might explain not all of them being listed in the UI.)

This turned out to need way more than what you mentioned deleting (apparently). I thought that simplistic approach might work, too - which is what I tried 1st. "It shoulda worked?!?" Yeah... "should have" & "did" are 2 different things.

I made a BU of prefs.js & then deleted 1st the basic lines you mentioned. That didn't make previewing personas work. And for the couple of persona names that showed in Addon Mgr, when they were enabled, had a few "glitches" in the GUI.

Like close buttons on tabs being kinda squirrely - not highlighting / activating the button consistently & things like that. I suspected it was connected to personas - & it was. I'm pretty sure this was all caused by personas (in some manner) - which is why I should've stuck w/ making my own backgrounds, which never caused problems.

Next deleted every line from prefs.js w/ "personas" in them. That didn't fix the preview / installing personas problem.

Maybe a line you wouldn't think affected personas was corrupted, that didn't contain that text (for searching), but by then I was fed up. I'd already tried restoring 3 or 4 BUs & all had the same issue.

So, created a profile w/ clean prefs.js, started TB, then quit. Opened what I thought would be a good copy of prefs.js - as far as email accts was concerned & copied basically all lines from an older prefs.js into the new one, that began with:

   mail.account.*
   mail.accountmanager.*
   mail.identity.*
   mail.server.*
   mail.smtpserver.*
   mail.smtpservers

That did the trick - - except for one acct. Like when taking an engine apart, the one bolt out of 8 that takes as long as all the rest put together. I eventually had to create that acct in Tools > Settings again, even though it was in prefs.js - like all the others.

Then had to delete .msf files for that acct in the profile before it showed the old msgs. And now it will show all the old msgs under that acct- when TB 1st starts, but after a couple min, they all disappear again & there are no replacement *.msf files created.