Updating Failed error

Hello. My site is WordPress 5.2.3 running Twenty Twelve Child theme.

I noticed yesterday that I could not save new pages. When I had the Classic Editor plugin on, the ‘Save Draft’ and ‘Publish’ buttons were dimmed. When I turned off the classic editor plugin, the buttons were active but I was getting an “Updating Failed” error. After disabling other plug-ins, I found that the seo-slugs plug-in was the cause.

I also received this message from my WordPress install:

Error Details
=============
An error of type E_ERROR was caused in line 33 of the file /home/ecftpuser/englishcurrent.com/wp-content/plugins/seo-slugs/seo-slugs.php. Error message: Uncaught Error: Call to undefined function split() in /home/ecftpuser/englishcurrent.com/wp-content/plugins/seo-slugs/seo-slugs.php:33
Stack trace:
#0 /home/ecftpuser/englishcurrent.com/wp-includes/class-wp-hook.php(286): seo_slugs(”)
#1 /home/ecftpuser/englishcurrent.com/wp-includes/plugin.php(208): WP_Hook->apply_filters(”, Array)
#2 /home/ecftpuser/englishcurrent.com/wp-includes/post.php(2362): apply_filters(‘name_save_pre’, ”)
#3 /home/ecftpuser/englishcurrent.com/wp-includes/post.php(2247): sanitize_post_field(‘post_name’, ”, 1971, ‘db’)
#4 /home/ecftpuser/englishcurrent.com/wp-includes/post.php(3414): sanitize_post(Array, ‘db’)
#5 /home/ecftpuser/englishcurrent.com/wp-includes/post.php(4028): wp_insert_post(Array, false)
#6 /home/ecftpuser/englishcurrent.com/wp-admin/includes/post.php(405): wp_update_post(Array)
#7 /home/ecftpuser/englishcurrent.com/wp-admin/includes/post.php(1931): edit_post(Array)
#8 /home/ecftpuser/englishcurrent.com/wp-admin/includes/misc.php(1122): wp_autosave(Array)
#9 /home/e

The site is running again with the plug-in disabled.