Yes, I have this issue.
I have five
gbwhatsapp website projects using NetObjects. Four export the template OK and produce the required zip file. I have just checked the contents of the directory it is saving to while exporting one of these projects (MyWebsite) and it created a file called zia08648 which changed to MyWebsite.zip as expected when NetOjects reported "Template has been saved".
The project which does not produce a zip file has a large number of high definition photographs. When exporting as a template a file called zia08648 is created as before and I tracked it reaching 906220KB (ie. approaching 1GB) after a couple of minutes before the file disappeared from file explorer, but NetObjects then still reported "Template has been saved".
I assume that the huge size of the zip file cannot be handled somewhere.
So with this project I backup the whole of the NetObjects User Site for it.
With a copy of this project I have progressively deleted pages with their photographs and eventually it exported OK as a template and produced the zip file.