Fatal error: Allowed memory size of 146800640 bytes exhausted (tried to allocate 57 bytes) in public_html/wp-includes/rewrite.php on line 1561

There really is nothing anyone here can do for you with such limited information. It is obviously something within your recent changes. If you use a version control system (as everybody really should), I would roll back the changes and then from there slowly re-implement the changes that were causing this error to track it … Read more

Error: options page not found

The action attribute in the form tag redirects you to the options page. But you also need a hidden field with the plugin slug. Normally its a hidden field that looks like this <input type=”hidden” value=”/wp-admin/options.php?page=[plugin-slug]” name=”_wp_http_referer”> where [plugin-slug] is replaced by your plugin slug.

WP URL /icons returns 403 forbidden error

Probably because /icons is a default path in the Apache server. AFAIK it can’t be changed/overriden in .htaccess, because it is defined as Alias in the Apache configuration. See, for example, this question on Stack Overflow: how to override index of /icons?