The reason of this problem may be that the antivirus you use blocks the browser process or interferes with its operation.
You can try to disable the antivirus and try to run ProjectMaker again and then run the template with the desired browser.
Sometimes the antivirus can even damage the browser process file. In this case only reinstalling the Zennoposter will help.
However, before reinstalling, you will need to add the working folder of the ZennoPoster to the antivirus exceptions.