The example below shows corruption in qt_add_qml_module() but it also happens when you add/remove files to, say, qt_add_executable(). It looks like there's a mismatch between the text and the text cursor.

Steps to reproduce

1. Load the attached project in Qt Creator and open CMakeLists.txt in the code editor
2. In the code editor, insert an empty line somewhere inside qt_add_qml_module() but don't save your changes
3. In the Projects view, right-click the main target ("appCMakeCorruptionBug") and select "Add Existing Files..." > "ExtraItem.qml"

Outcome
You end up with a corrupted CMakeLists.txt like

qt_add_qml_module(appCMakeCorruptionBug

    URI CMakeCorruptionBug
    VERSION 1.0
    QM
    QML_FILES ExtraItem.qmlL_FILES Main.qml
)

Workaround
Get into the habit of saving your project before adding/removing files