Hi Kier, the memory usage needed depends greatly on the size of the original Product images that WordPress is resizing into thumbnails. If you can confirm the size and dimensions of some of these images as well as the image import method you’re using I can give you an indication of what the memory_limit should be set to. If you find the importer is timing out on the same Product it could be a time limit that’s being reached and PHP is terminating the process.
To start I’d bump that 50M up to 96M and confirm if this sorts the 500 error.
