It doesn't happen often, but when it does, it's a Real Pain ! This has been happening for the past year or two. Opera crashes, and upon reloading, either:

1. All saved tabs And workspaces are gone!
   or
2. My created workspaces are gone and all tabs are Smooshed into the default workspace.
   Is there any built-in facility or any extension which will backup and Restore all tabs And Workspaces after a crash??
   My current solution is to have my system backup program back up the entire "Opera Software" directory 3 times per day so at Worst I'll only lose a few hours of browser tab/workspace activity. I hope you can suggest a better/easier way to get my workspaces back after a crash, or maybe avoid the crashes in the first place. Thank you very much!

@lremery CCleaner to the rescue!!
finally I can confirm that this double-tabbing problem is no more!
I was clearing up a totally unrelated problem and after I was done, I ran both CCleaner's system cleaner and the registry cleaner. Soon after, I was shocked and delighted when I clicked on a link in Thunderbird and only one tab was produced! I was all set to delete the extra tab, but it wasn't there! I don't know which of the two CCleaner tools I used actually did the trick. I hope that anyone else who still suffers from this issue finds that CCleaner gets rid of it for them too! Give it a try! May the best outcome be yours!

I've been searching for a good Session Manager which will save all of my active tabs - as well as - my workspaces - at set intervals - so I'd be able to restore everything in the event of a crash.
My newest solution is to have system backup program back up the entire "Opera Software" directory 6 times per day so at worst I'll only lose a few hours of browser tab/workspace activity. I hope you can suggest a better/easier way to get my workspaces back after a crash.
I don't remember exactly when I discovered workspaces, but they're SUCH an organizational convenience! At that time, I believe that Opera was the ONLY browser with them... I'm not sure if that's still the case - or - how far back that workspaces were enabled in Opera. Regardless, I'm addicted to them now, and sometime just before or after I discovered them was when the tab-killing crashes began occurring more frequently. Sometimes Opera crashes and does not kill my tabs or workspaces. But when it does now, at least I have a few-hours-old backup I can use to get most of my tabs back. I hope that someone has created an extention/utility that supports the easy, seamless restoration of both tabs and workspaces! Someone out there please let me know.
Thank you very much!

No, I STILL haven't found ANY session manager which handles Opera's workspaces. Thank goodness Opera hasn't been failing with anywhere near the frequency it HAD been in the past. Still, in order to completely eliminate my tab/workspace-loss worries, I now back up my ENTIRE "Opera Software" folder (as well as my Thunderbird profile folder and my ECCO Pro folder) 6 times each day. Opera has garbled up SEVERAL times since I started backing up so regularly, but at most I only lost a few hours of browsing history or e-mail. Thank goodness for the nice quick restoration process!
Just realized I already wrote about my backup process in my initial message!! However, the work saved by my backups makes the redundancy of my suggestion worthwhile. I cannot overstate how important these backups have become to maintain my peace of mind!!

@lremery CCleaner to the rescue!!
finally I can confirm that this double-tabbing problem is no more!
I was clearing up a totally unrelated problem and after I was done, I ran both CCleaner's system cleaner and the registry cleaner. Soon after, I was shocked and delighted when I clicked on a link in Thunderbird and only one tab was produced! I was all set to delete the extra tab, but it wasn't there! I don't know which of the two CCleaner tools I used actually did the trick. I hope that anyone else who still suffers from this issue finds that CCleaner gets rid of it for them too! Give it a try! May the best outcome be yours!

@goddesirae What remedies have you attempted - anything I haven't already listed above? I ** love ** Opera! The only problem I currently have with it is this damned double-tabbing. I open external links very frequently. What a pain is is to hafta close one of 'em each and every time!

#1) I wonder how many more Opera users are suffering through this issue?
#2) What on earth will it take to get the attention of Opera developers and have them fix this??

How difficult could it be? Some sub-routine some-where... is callilng for the creation of an externally-addressed tab one additional time. They should just find it and fix the code.
I'm begging them!?!

It's been almost 2 months since I first posted this issue... and I'm still getting double-tabs (duplicates) each time I click on any link from Thunderbird or any other non-Opera (external) link. Can anyone anywhere out there figure out a possible reason two identical tabs would be created any time any external http link is clicked on?? Please help.

Ok... just to assure all support personnel - I performed each and all of the steps outlined in the instructions for this section of the Opera forum:
Disable all extensions

Reset settings to default (Do a backup and export your passwords first)

Reset flags to default

Create a clean profile folder/directory

Check if your Operating System is up to date

...and I still am getting two identical tabs each time I click any external links.
Someone please help!! Thanks!

Just updated browser to version:
Opera One(version: 105.0.4970.29)

Still getting double tabs each time I click external links...

Still no ideas for a solution??

Still no ideas for a solution??

@burnout426 Well at least I see that I'm not alone!
Like 'Ralf-Brinkmann', I've tried closing and restarting Opera - as well as rebooting my system a number of times - but I haven't had the good fortune that he had (though he was working with a different version of Opera). Mine still doubles each tab after clicking links from other applications. I've even got two windows open on two separate monitors, and links directed to either window yield the same duplication of tabs! I surely hope that someone here can help me out of this annoying mess! Thanks!

Every time I click on any link which is not in the browser (Thunderbird, Acrobat, Word, etc.) two identical tabs are created! When I click on any link within the browser, all is normal with only one tab being created. This happens consistently, without exception.
This double tab creation just started happening probably between one and two weeks ago. I did install the current version update at around that same time, so this tab duplication issue may be related. Please help! Thanks!

Currently using Opera Version:
Opera One (version: 105.0.4970.21)
Windows 10 - 22H2

For me, Opera has been a bit spotty with auto-updating. Sometimes Opera will allow me to initiate it's auto-update, but after it restarts, it's still the same old version. Often I have to download the latest Opera installation file, shut Opera down, and install the latest version manually in order to update it successfully. But that's a matter for its own support request if it ever becomes bothersome enough.
In 2017 I started using Opera while my primary browser was Firefox. Opera's been my primary browser since about 2019.
Can't live without workspaces!
Have little/no use for Tab Islands...
Thanks again!!

Also:
This (double tab creation) just started happening probably between one and two weeks ago. I did install the current version update at around that same time, so this tab duplication issue may be related.
For me - Opera has been a bit spotty with auto-updating. Sometimes Opera will say it's auto-updating, but after it restarts, it's still the same old version. Often I have to download the latest Opera installation file, shut Opera down, and install the latest version manually in order to update it successfully. But that's a matter for its own support request if it ever becomes bothersome enough.
In 2017 I started using Opera while my primary browser was Firefox. Opera's been my primary browser since about 2019.
Can't live without workspaces!
Have little/no use for Tab Islands...