Allowed memory size of 41943040 bytes exhausted tried to allocate 89 bytes.

To solve this problem you have to increase memory limit
First you need to edit the wp-includes/default-constants.php file on your WordPress site. It is located in your WordPress site’s root folder, and you will need to use an FTP client or file manager in your web hosting control panel.
Next, you need to paste the following code in wp-includes/default-constants.php file just before the line that says ‘That’s all, stop editing! Happy blogging.’

define( 'WP_MEMORY_LIMIT', '256M' );

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