I cannot select a object on screen even after adding the object class to MSAA option

Hi hina 

Have you tried adding custom controls to the mapped objects 

https://support.smartbear.com/testcomplete/docs/working-with/managing-projects/properties/object-mapping.html

Its difficult to tell exactly what the issue is, however mapped objects shows you what objects TC support out of the box. 

MSAA/UIA extends what we support out of the box. 

Using mapped objects, you can then add additional classes, perhaps classes which derive from a supported classes or custom classes etc. 

Try it out, see you get on. 

Failing I would suggest arranging a call with an engineer potentially opening a support case. 

It will be easier to find out whats actually happening. 

Your SmartBear rep can arrange this

KR

Vincent