MacOS Sierra - Tab Bar showing in Stack and IDE windows?

[James Hale]

Check you Dock preferences.

When Sierra came out I too was looking forward to this feature having gotten use to tabs in other apps. 
One app I use quite a lot is Nisus and having tabbed windows rather than multiple windows was going to be a real plus, or so i thought.
Sadly tabbed windows was not present and so I wrote to their support asking if it would be.
They said they would add the request for a possible future update but also added....

> One tip: apparently you can adjust how Sierra's tabs behave in all application, including Nisus Writer, in your system Dock preferences. You can change the setting for "Prefer tabs when opening documents" so tabs are more often retained. This doesn't cover all your requests, but might help you improve your workflow.

And so I did, setting it to "Always" and voila, tabbed windows.
A few days later I opened LC and was dismayed to see exactly what you have described.
I played around with different windows etc but quickly realised that having all new docs open in a tabbed window was not something LC liked.

I turned this "dock" preference to "In Full Screen Only" and have not had the issue return (I do not use fullscreen mode for LC)

So perhaps your Dock settings and the way you are using LC are triggering this feature of Sierra.

James

james at thehales.id.au

Tel: +61 3 9386 2516    
Fax: +61 3 9386 1387