Warning at the Transactions page after the plugin update

I've just updated Appointments+ from version 1.4.2 to version 2.2.3 and I have a problem. If I go to Transactions and look at the Service column, I see the following errors for each entry.
Warning: Illegal offset type in isset or empty in /home2/sriom99/public_html/***hysio.com/wp-includes/cache.php on line 700 Warning: array_key_exists(): The first argument should be either a string or an integer in /home2/sriom99/public_html/***hysio.com/wp-includes/cache.php on line 700 Warning: mysql_real_escape_string() expects parameter 1 to be string, object given in /home2/sriom99/public_html/****hysio.com/wp-includes/wp-db.php on line 1111 Not defined

We can hide warnings, but in Service column, all services show as Not defined.