Fresh installations with default php.ini settings e.g. on cPanel with memory_limit of 64MB won't working.
Thanks
What was the error message that you got? And what is default php.ini?
memory_limit value depends on your store size and number of visitors. We usually recommend to set it to 256-512M, this should be enough for most installations.
It's already set to 256M if the sever is a 64bit server running 64bit PHP.
Take a look at config.local.php
I'm guessing their assumption is that if you're running on an old 32bit server that you probably have a smaller store and your export/imports (biggest user of memory) will work within 64MB. Not usually an issue on the customer side other than some image manipulations.