This is not a plugin issue. Check with your hosting company to see how much PHP memory is allocated for you. There is no definite value to be set at but if possible try for 64 to 128MB.
You can also try increasing the memory limit within WordPress via your wp-config. I’d give that I try first, bump it to something like 128mb and see if that helps.
https://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP
Thanks for all the replies. My host’s limit for me is 128. Even after editing wp-config.php it still gives me an error: Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 7680 bytes)
Thanks.
Adding memory to the WordPress config will not work for every host. Again, it is best you ask your host to bump this up for you.