error in latest wordpress

We just received this error message from our wordpress system:
We forward it, maybe it’s a real issue.

Error Details
=============
An error of type E_ERROR was caused in line 36 of the file /home/admin/domains/xxx.com/public_html/wp-content/plugins/gravity-pre-submission-confirmation/gravity-pre-submission-confirmation.php. Error message: Uncaught Error: Class ‘GFFormDisplay’ not found in /home/admin/domains/xxx.com/public_html/wp-content/plugins/gravity-pre-submission-confirmation/gravity-pre-submission-confirmation.php:36
Stack trace:
#0 /home/admin/domains/xxx.com/public_html/wp-includes/class-wp-hook.php(288): GFPreviewConfirmation::replace_merge_tags(Array)
#1 /home/admin/domains/xxx.com/public_html/wp-includes/plugin.php(208): WP_Hook->apply_filters(Array, Array)
#2 /home/admin/domains/xxx.com/public_html/wp-content/plugins/gravityformspartialentries/class-gf-partial-entries.php(391): apply_filters(‘gform_pre_rende…’, Array, false, Array)
#3 /home/admin/domains/xxx.com/public_html/wp-content/plugins/gravityformspartialentries/class-gf-partial-entries.php(745): GF_Partial_Entries->maybe_save_partial_entry(72)
#4 /home/admin/domains/xxx.com/public_html/wp-includes/class-wp-hook.php(288): GF_Partial_Entries->filter_heartbeat_received(Array, Array)