Hi

Whilst this is a more technical answer, I recommend you install and try the About Sync add-on for Firefox.

Using this you can easily access the Sync logs and have insight into the data that you are sending to another device.

I hope this helps, but if not, please come back here and we can look into a different solution for you.

I notice that you are using an older version of Firefox. I strongly recommend you update to make sure that you have the latest security and stability fixes as well as new features. You can read more about how to update here.

1. Sorry Seburo, I am thinking that would open up the security risk I am trying to avoid (e.g. I dont want to turn Firefox Sync on). I would like to know what is stored by Firefox from a Sync perspective and could not find anything in searching.
2. I do not update Firefox until all my addons are good on the current version. Firefox has cost me heaps of time on a simple upgrade gone wrong. I don't find these geneic answers "please upgrade" at all helpful as it does not get the pain an upgrade has been in past. I am terribly sorry. such comments encourage me not to share what firefox I am using. Perhaps when I have the joy of upgrading painless, 2 in a row, I may have a different perspective. I still have things lost and no answers from my prior upgrade e.g. I use to be able to cick on space after my pinned tabs to create a new tab. Not any more since upgrade and no addon apparently does this. So likely a legacy of the addon TabMix Plus that caused so many issues with my firefox.

Hi again jendrew, Sebruo's advice is good and well intentioned. Although I also recognise your viewpoint and problems.

Of course we can not guarantee Firefox will be perfect. In fact the Release is deliberately throttled after it goes out so not everyone gets it before we get feedback from the first to use it. Before that it has gone through from the Nightly to the Developer Edition then the Beta channel.

Yes you could be cautious and hold off in updating but that has to be balanced against you then risking from what were zero day exploits now being open for all to exploit with the holes fixed and publicised

Although rather counter intuitive I have often suggested more advanced users should head in the other direction. Run Beta as your your day to day browser

• You get any new features 6 weeks head of the majority
• It is pretty stable.
  • In fact most times I run Develper Edition, and have done for years (it was Aurora). It will break extensions but otherwise is pretty stable.
• Any problems drop back to the Release. Once you have been on Beta for six week cycle the you will have effectively already tested the up coming Release with whatever you are going to throw at it. It worked then it sure as heck will work if you have to fallback to it because of any glitch in Beta.
• If you test the Pre-Releases and an add-on breaks you can not only fallback to Release but report the broken add-on. With any luck in future whatever add-ons you use will be fixed before Release because of your feedback, and if not you have chance to think of workrounds or alternatives

Even if you do not wish to use a PreRelease version day to day it may be worth considering trialling PreRelease versions just to give you a headsup, or much less controversially just trial the Release even if you are not willing to use it day-to-day.

Of course if you are part of an organisation you may instead opt for the stability of ESR that is not intended for individuals to use but it does get all critical security updates.

P.S. That is apparently a great add-on that seburo linked to, although I have not actually tried it myself Have you also seen

• How do I submit a bug for Firefox sync?_sync-error-logs

Thankyou John99. Very Helpful again.

1. Good to know you have heard good things about the suggested addon
2. AboutSync - I posted a question on add-on developers github, earlier, to clarify my assumption that to use this addon, one must have Firefox Sync Activated.
3. How do I submit a bug for Firefox sync?_sync-error-logs -- Thankyou. I thought/assumed this was for a bug with the actual sync process.

on the side issue:

1. Suggestion of alternate upgrade perspective -- I will need to digest this as its a big change for me. Your point re: zero day exploits is very helpful. Never considered this and this could make me change. Thankyou for informing me more completly. Even the recent change by Firefox not to allow some addons that had not had this certification or something cost me lots of time. As it meant all of sudden one day one of the addons I rely on does not work e.g. the addon show me more prior saved options in bookmark save history which i use all day every day. Simple things like that. This is still broken to do this day as that addon didnt get fixed and I have not had time to write to developer etc...
2. I think I have to get much more comfortable at reverting back if something goes wrong. I am just not very comfortable on this. Although I back up my profile using FEBE (great addon). The time to revert back to my old profile from problem detected in say new upgrade i have not managed to get less than 2hrs. Often I simply do not have spare 2hrs.
3. Trialing would never work for me, as I find its the unexpected things that catch me off guard with upgrades, rather than the things I would even think to test e.g.

• Bulleted list itemnew tab by double click on space of pinned tab disappeared
• Saving a new bookmark the addon that showed number of saved options was disallowed

I was going to hazard a guess that you would not need Sync active to use that add-on but I temporarily installed it to check.

Whereas you will be able to view the weave.log whether or not Sync is active and whether or not you are signed in to your Firefox account the About Sync add-on requires you to log in to the Firefox account before it will display information.

Firefox breaking add-ons without prior warnings. That is one of my pet hates, and judging from the posts we get must annoy a lot of people and probably cost Firefox in terms of market share. I have repeatedly commented that it should at the very least warn users of the add-ons it is about to disable or break and give them an option to abort the upgrade. Even if users were to have a day or two warning they could consider alternatives or finish vital work.

Over aggressive promoting the Refresh option without a prominent warning that all add-ons are about to be removed is another thing I don't think is good idea.

Version Changing I always have multiple versions installed. That is relatively easy to do. So I can choose which version to run by for instance clicking its shortcut. Right now I have two separate versions running side by side.

A few years back they experimented with a simple method of changing (channels) versions from the User Interface but the idea got shelved. I think anyone using multiple versions must use a separate profile per version. Once you decide on that using multiple versions is easy. In fact not too long ago the pre release Alpha was rebranded from Aurora to Developer Edition and made so that by default it installed as an additional browser with its own profile.

Firefox profile management is work in progress. There was a standalone profile manager but that fell into disrepair. There is a built in one but it uses a comandline so is not too use friendly. There is a new one built in about:profiles but that only partly works. Of course there is always Firefox Sync !! that is not intended as a backup it is intended to Sync between devices (The new version will act as backup - but you certainly should not rely on it doing so). Sync will of course Sync between multiple Firefoxes set up on the same computer.

If you or any reader of this thread are interested in running multiple versions take a look at these

• Profile Manager - Create, remove or switch Firefox profiles
• https://developer.mozilla.org/Firefox/Multiple_profiles
• http://kb.mozillazine.org/Testing_pre-release_versions

Trialing would never work for me, as I find its the unexpected things that catch me off guard with upgrades, rather than the things I would even think to test e.g.

If you run beta as the day to day browser just drop back to Release. Once you have done a six week cycle on Beta you would not expect to come across any issues on a the Release that you had not already encountered, so if the Beta upgrades and you have issues temporarily drop back to Release and all the new Release is, is a Renamed Old Beta so you know it works.

Developer verified you need the Firefox feature, "Sync" active to use the addon "AboutSync"