If your smart you will update, The main reason for updates is to fix dataloss bugs and security holes. Actual changes to the program are really secondary and somewhat unusual in the point updates.

36.5 is basically the same as 38.6 with some critical bugs fixed. However some anti virus products. Those sold by Symantec under the Norton brand particularly have difficult coping with software updating.. They expect a full install. So if you have difficulties go to getthunderbird.com and perform a full install.

One thing we have seen in this forum over and over is that windows restore has a nasty habit of corrupting Thunderbird profiles. It is more of a last resort than a nice convenient way to back up of some difficulty.

To be clear. I was using Thunderbird 38.5.1 and all was working well. When an update was applied the new version did not work. I did a system restore back to 38.5.1 and then Thunderbird says that I should update. When I agreed, same problem again. Now when I use 38.5.1 the screen prompt comes up "Do you want to allow the following changes to this computer? ... Mozilla Corporation" Will this prompt come up forever? What is the solution? I can't imagine performing a new fresh download where I will have to completely personalize with the address books and personal settings!

addison45 said

To be clear. I was using Thunderbird 38.5.1 and all was working well. When an update was applied the new version did not work. I did a system restore back to 38.5.1 and then Thunderbird says that I should update. When I agreed, same problem again. Now when I use 38.5.1 the screen prompt comes up "Do you want to allow the following changes to this computer? ... Mozilla Corporation" Will this prompt come up forever? What is the solution? I can't imagine performing a new fresh download where I will have to completely personalize with the address books and personal settings!

To be clear, I have no interest in windows restore, other that the fact that I have wasted more time on this forum trying to sort out corruption caused by it that I ever want to do again. I now simply do not reply to issues caused by windows restore. You make the mess, you dig your way out.is my approach now.

Yes I ignored your question, I resolved the underlying issue instead. Sorry about that. But I am done here.

What choice did I have but use system restore? The update didn't work.

Have you checked your anti virus and it's firewall allow Thunderbird access to the internet?

Failure of a Thunderbird update to work has to possible reasons that account for about 99.9 percent of issues. The other not covered by anit virus issues is handled by restarting in safe mode with add-ons disabled. That is on the help menu.

Both things are preferable to doing what you did. If you new car has a flat tire, do you go back to the dealer and ask for your old one back?