Maximum execution time of 30 seconds exceeded

Greetings, I love your plugin, and it has worked faithfully for some time. recently I noticed I had pages that were failing to load. The menu bar would come up, and the page heading would load, but nothing else, not even the admin bar. I turned on debug mode in wp-config, and on some (but only some) of the pages, I get the following message:

“Fatal Error: Maximum execution time of 30 seconds exceeded in” …. [domain and directory] …. “wp-content/plugins/linkify-text/linkify-text.php on line 288”

Line 288 is part of this function:
// Check if the text contains the phrase to link.

Specifically:
$has_text = mb_ereg_match( ‘.*’ . $regex, $text, $preg_flags );

I don’t know enough about code to be able to tell if I am having a conflict between plugins or themes or if I have done something wrong here. I have not modified the plugin, and I am not on a child theme.

The plugin has been deactivated for now, so that the page, which I was in the process of actually creating, can continue to work for me while I play around with it.