Note: Connected applications have been deprecated. Quote from https://support.smartbear.com/testcomplete/docs/testing-with/advanced/connected/about.html
"Connected and Self-Testing applications are deprecated. These technologies will be removed in one of the future releases of TestComplete.
To create test code that runs from within your tested apps, use TestLeft, a SmartBear functional testing tool for developers. "
Considering this, it is entirely likely that compiling a connected application using VS 2017 will fail. I am not a SmartBear employee so for an official answer, it would be best for you to contact support directly at
