PHP Fatal error: Uncaught Error: Cannot use object of type WP_Error as array

I am getting a PHP error which is causing GravityForms to stall and will not complete the submit process. This is causing a server 500 error and here is what was found in my server error log:

PHP Fatal error: Uncaught Error: Cannot use object of type WP_Error as array in [WEBSITE]/wp-content/plugins/convertkit-gravity-forms/components/gravityforms/class-gf-convertkit.php:165
Stack trace:
#0 [WEBSITE]/wp-content/plugins/convertkit-gravity-forms/components/gravityforms/class-gf-convertkit.php(281): GFConvertKit->get_custom_fields()
#1 [WEBSITE]/wp-content/plugins/gravityforms/includes/addon/class-gf-feed-addon.php(308): GFConvertKit->process_feed(Array, Array, Array)
#2 [internal function]: GFFeedAddOn->maybe_process_feed(Array, Array)
#3 [WEBSITE]/wp-includes/class-wp-hook.php(288): call_user_func_array(Array, Array)
#4 [WEBSITE]/wp-includes/plugin.php(203): WP_Hook->apply_filters(Array, Array)
#5 [WEBSITE]/wp-content/plugins/gravityforms/gravityforms.php(5458): apply_filters('gform_entry_pos...', Array, Array, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
#6 [website folder] in [WEBSITE]/wp-content/plugins/convertkit-gravity-forms/components/gravityforms/class-gf-convertkit.php on line 165, referer: [WEBSITE]

Is there a fix I can add to the code? Do you need to update anything?

Please advise.

Thank you in advance!