Reading and translating his further posts, it appears as though there is a size limit to a saved project. Exceed that limit, and the project re-opens as a blank "New Project". You get no warning when clicking on "Save Project", you can even do a "Save As" as a backup, but he reports that neither project will re-load.
Here is his latest post, translated using Google Translate.
Conducted an experiment.
I made sure that the number of elements used is limited! When a certain number of elements is exceeded, the project stops opening. Moreover, working with the project, you can add as many elements as you like, everything works fine, visually saving occurs (the asterisk next to the project name goes out) when you click on "save", and you understand that "you got it" only after you close and try to open the project!
Experimenting with the "label" and "text string" elements. The number of elements is also affected by the "weight" of the element. For example, the more characters in "tags", the less the total number of elements will be. But the size of the "text lines" does not affect the number of elements. With default settings, a maximum of 109 labels and 194 text lines can be set (303 items in total). After that, the saved project will no longer be opened.
It turns out on the server there is a limit on the size of the project, if exceeded, some kind of failure occurs.
I would very much like the developers to solve this problem.
This is indeed a major bug in the system, and definitely needs addressing by the developer.
Everything works with smoke - if you let it out, things stop working....