@simcard78: I feel your pain.

Tab stack are back, kind of. There should be option to "Move tab to Workspace X" in somewhere.

@pepik110: I just came here to inform the same. Random crashes occurs.

@ralf-brinkmann: Excellent news. I hope next weeks version bring this to Developer version too. It would ne nice to see what kind of actual code changes this fix needed.

I'm not sure if this is related to this build but I updated my browswer with two windows open. After update the second window (which have only 3 tabs) does not allowed clicking tabs. Address bar etc. works but I cannot change tabs and tabs does not contain close x's - I could close those tabs via CTRL+W and window closed after the last one. Reopening last closed tab opened new windows and then tab contains closing button. It's weird and could be coincidence but thought to share it anyway.

@ralf-brinkmann: I think I would like this feature IF i could teach myself to use fa less tabs. I've switched from Workspaces to Tab Island but still quite a mess. I like that Opera allows many ways to arragen tabs - problem is me.

@krishnakrverma: Opera is based on Chromium - and adds features and modifications to that. New features or popup-windows or changes are made of Chromiums. => all of those should be inspected and if necessary modified by Opera. So herecould be the BUG: Sometimes all of those changes are not noticed and this can happen.
But also we all know that we are using Developer version - which allows testing of premature version of Opera. It's better to allow big changes to being tested than waiting that every single detail has been fixe. When Developer moves to Next it's still unfinished and will contain bugs. And so called stable version always contains bugs too.

@pclaudel1: I think she meant that bug is identified and fixed internally and we see the fix when next developer build is published. Probably next monday or tuesday. Very annoying bug - I forgot that and always crashed twice when searching for tab. (That's a problem with tab-o-holic with about 250 tabs

Fascinating that Chrome has been in stable version 138.0.7204.158 in 15.7. and now is on stable 140.0.7339.881. Of course Opera must test their own code with it but still I would think that at least Opera Developer could(should) be quite near the Stable version of Chrome. But of course this is neverending race. I still occasionally test Vivaldi but always come back to Opera. Other options are not for me.
It would be fascinating to see under the hood how the process is done in Opera. Who decides that version is selected for next branch and can they jump over something. (OK we will skip 139 branch completely etc. - OK Chrome 139 was released month ago and Chrome 140 two days ago. So I will already regret this message but the sake of conversation send it anyway.

Just the sake of curiosity because of Opera user since 3.6 - I have missed something but what are meaning of RNA in changelog? I think CHR is Chrome/ium and DNA is normal bugs but RNA seems to start in smaller number and it started couple of builds ago in 122-series?

@pclaudel1: I think she meant that bug is identified and fixed internally and we see the fix when next developer build is published. Probably next monday or tuesday. Very annoying bug - I forgot that and always crashed twice when searching for tab. (That's a problem with tab-o-holic with about 250 tabs

@krishnakrverma: Opera is based on Chromium - and adds features and modifications to that. New features or popup-windows or changes are made of Chromiums. => all of those should be inspected and if necessary modified by Opera. So herecould be the BUG: Sometimes all of those changes are not noticed and this can happen.
But also we all know that we are using Developer version - which allows testing of premature version of Opera. It's better to allow big changes to being tested than waiting that every single detail has been fixe. When Developer moves to Next it's still unfinished and will contain bugs. And so called stable version always contains bugs too.

I did'n (as far as I know) change any settings but I have too much tab and tab islands and with this version when I choose tab the tab bar does not always stay in that place at alla. So I have island with couple of tabs in same domain and I choose one but after that tab bar does not show this tab island and I must scroll tab bar to find it. Has anyone noticed this kind of behaviour? After update I have used ai to arrange tabs to tab island.

@dazung: Thanks! That worked.

@koimark: Continuing my monologue. Disabling all the extension did not help. Version 121.0.5558.0 works but 5565 and 5566 does not work. I would like to keep my tabs, passwords etc. intact.

@koimark: Same happened today after coming back to work. Computer was restarted and opening Opera with old exe worked. Then update notification came and after that restart blinks task bar icon and does not start. (This in Windows 11 23H2) - after switching back to old opera.exe it worked again. Home computer with macOS Sequioa no similar problems with newest update. Could be related to some extension but yet have no time to check. New crash reports were generated so I hope maybe someone in Opera could comment if crashreports shows what could be wrong.
I have these extensions in use:

Browserling - Cross-browser testing
Versio 1.0.2 tekijältä browserling

F.B.(FluffBusting)Purity
Versio 37.4.2.0 tekijältä st333v

Google Docs offline
Versio: 1.92.1

Install Chrome Extensions
Versio 2.5.9 tekijältä Opera Software

KeePassXC-Browser
Versio: 1.9.8

No YouTube Shorts
Versio: 0.6.6

Open in PDF Reader
Versio 0.3.6 tekijältä andy-portmen
Send PDF links directly to your favorite PDF viewer like Adobe Acrobat Reader

Open Multiple URLs
Versio: 1.7.5

Opera Ad blocker
Versio: 121.0.5558.0

Remove Google Redirection
Versio 1.1.1 tekijältä kodango

Web eID
Versio: 2.3.0

@koimark: I found crash logs and some of them was sent. Tried also manually add couple. Now trying maybe to restart computer and later try again.

Warning! Boot loop after update for me and my precious pile of over 250 tabs . Just blinks couple of times when starting. Renaming new opera.exe and then restoring C:\Program Files\Opera developer\opera.exe.old -> opera.exe and Opera starts just fine. I don't knows was crash reports generated or not.