Hi Ole Myrbakken,
We are able to reproduce the issue “NewButton disappears on
TabControlExt”, however to access this, we request you contact us at Syncfusion
Support or you may also create your customer account under Direct Trac and open
a new incident so that our support engineer will assist you accordingly.
Our Direct Trac support system can be accessed from the
following link:
https://www.syncfusion.com/account/login?ReturnUrl=%2fsupport%2fdirecttrac%2fincidents
Regards,
Berkunath A