Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.0
• Cross-platform modules: 6.0.2
• Android Runtime: 6.0.0
• iOS Runtime: 6.0.0
• Plugin(s):

Describe the bug
Have one tab structure defined in XML. On click I want to change the tabs to something else. Doing so cause the app to crash.

To Reproduce
https://play.nativescript.org/?template=play-tsc&id=qn90jL&v=2
Tap on the Change button

Expected behavior
To work 😀

Related to #6967