Warning: Missing argument 2 for wpdb::prepare()

Hello Experts,

When my subdomain endangeredhawaii.lisachau.com loads, it first shows an error for a second before loading the page-
Warning: Missing argument 2 for wpdb::prepare(), called in /home1/lisachau/public_html/wp-content/mu-plugins/domain-mapping.php on line 511 and defined in /home1/lisachau/public_html/wp-includes/wp-db.php on line 1275

This error showed up after using the wpmudev domain mapping plugin. I am using the Divi theme from elegant themes.

Here are things I have done:
-I turned off all other plugins, but error still shows up.
-I have asked for support with Divi from elegant themes. I am reluctant to attend switching themes to a general wordpress theme to test if it is the Divi theme, because I will lose all the customizations within Divi (I will have start from scratch).
-I've read other posts in wpmudev about the same error, which seems to fix itself if you update everything, which I did. (Previously my website was supported by my old partner. I signed up for myself, skipped the trial period, and updated everything hoping it would repair the error.)

Thank you for your help,
Lisa