Output for Microsoft HTML Help's CHM won't open: File is only 1KB!

I updated RH 2020, trial version.

I selected the Microsoft HTML Help preset, which I finally find due to someone named Peter.

I configured the preset: I selected the TOC file. I specified the output folder, which is on a different drive than the project folder. (I knew that it could not be in the location whose parent folder was the project folder.)

Then I clicked the command button to generate the CHM. The progress display continuously indicated the various task that were being performed during the generation process.

Ultimately, I clicked the View Output button. The program displayed an error message indicating that the CHM filed could not be opened. I checked the output designation folder; and, the file existed. However, it was only 1 KB. I double-clicked the CHM file; but, the same error message appeared as when I attempted to open the file from within RoboHelp.

As an aside, I tried he same process  (i.e., MS HTML Help creation) with RoboHelp’s sample project, namely, Compass Travel. And, wouldn’t you know it? The CHM file did properly generate and display; even the bookmarks functioned as expected.