Please don't double post your questions. I have deleted your previous one since it is the same as this one.
I just checked my 17 and I can save to BimX from the "3D Window" without problems. Just to be sure, you cannot save from a 2D Window to BimX. Also there is no problem publishing to BimX Docs.
Eduardo Rolón AIA NCARB AC27 US/INT -> AC08
Macbook Pro M1 Max 64GB ram, OS X 10.XX latest another Moderator
Maybe you imported your Work Environment from a previous ARCHICAD version and in that version the File menu did not contain the "Save As BIMx" command.
You can add it to the File menu in the Keyboard Shortcuts page of the Work Environment Dialog.
Get Archicad Tips at https://twitter.com/laszlonagy AMD Ryzen 1700X CPU, 48 GB RAM, Nvidia GTX 1060 6GB, 500 GB NVMe SSD 2x28" (2560x1440), WIN10 PRO ENG, AC20-AC26 Loving Archicad since 1995