I have come across this several times. For me it crashes 3ds Max after denoising is done. If I cancel in time before denoising finishes then it won't crash but I get the error you're showing when saving as CXR.
For me it's always the RAM filling up (even though i have 128gb) and then the page file on the hard disk also filling up. So little RAM + little space in the disk = crash.
Try optimizing the scene, less render elements, smaller resolutions, invest in more ram + disk space.