Hi,
We apologise for the inconvenience caused. For some reason I am unable to reproduce this issue. Please refer to the sample attached. In the sample, I am adding dynamically creating tabControlAdv and adding tabpages (say 500 pages) to it. Refer to the time it takes to complete this action.
Also, let me know the Essential Studio version and OS version which you are working on.
Regards,
Mano
Sample_TabControlAdv.zip