I opened an original shapr3d file with the size of 133mb, which is the usual. I worked on it and then saved it as a working version. I tried opening this version today and it crashes my entire system stating my memory has run out, which it would as it is trying to open a 3.5GB file.
Could you open a ticket in the link you posted? We need access to the file to investigate the problem.
Also, please note that the size of the .shapr file, and the memory it requires to open, are two different things, which aren’t always closely related. It can happen that a project of this size requires more than 3GB ram to open.