If you open a large number of big images in MaxIm DL you could potentially run out of memory. This is particularly true because MaxIm DL works on images in floating-point format, which means 4 bytes per color plane. This can add up quickly with tricolor images plus the display buffer.
The good news is that MaxIm DL is designed so you never have to open a large number of big images! In most cases you should need to open only a few images at a time. Some important points:
Stacking - do not open all your images and then try to stack them. Instead, use the Stack command's ability to read images directly from disk.
Image Calibration - there is no need to manually stack calibration images. Simply load them from disk via the Set Calibration command. Stack can also calibrate, and color convert (de-Bayer) images on the fly, so you don't have to pre-process them.
Photometry - the Photometry command can load images directly from disk.
Batch Processing - in the event that you wish to perform the same steps on multiple images, use the Batch Process command. Advanced users can also use the COM/ActiveX Scripting features.