[Paul Wong-Gibbs]

No upper limit, but you have a memory limit. Read this -> https://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP <- and try setting it to 96Mb.

If the change doesn’t do anything (i..e. the “allowed memory size” is exactly the same in the error message), contact your host and ask them to increase the PHP memory limit for you.