Ensure that your Microsoft Visual C++ Redistributables are up-to-date. Updates from Microsoft for their Visual C++ Library Redistributables includes bug fixes for existing Microsoft Visual C++ Redistributables that for a few users has solved rare and user specific issues related to the Nextion Editor starting properly. For most users, the Redistributables are updated automatically in their periodic Microsoft Windows Updates.

Visual C++ Redistributables can be found [here] on the Microsoft website.