Error message when creating Qt Designer Custom Widget project with CMake

This refers to version 3.1.0.44, which is not listed in Jira.

Try creating a new Qt Designer Custom Widget using CMake as build system. Although the project seems to be created in the background, MSVS displays a cryptic error message: "Value does not fall within the expected range."

At the very least, the error message should tell the user what went wrong and how to solve that.

Found while extending Squish test tst_new_project_file_creation.