Catchable fatal error – PlanSo Forms plugin

Hi to everyone,

this is my issue: the plugin PlanSo Forms use to work perfectly on one of my websites, both desktop and mobile version are perfect.
On my second one the desktop version was perfect, the mobile not.
Wrote few times to the PlanSo support but never had answer back.

Few hours ago there was an update for this plugin. Did it. Now on the page (both desktop and mobile) appear ONLY this thing:

” Catchable fatal error: Object of class stdClass could not be converted to string in /home/content/p3pnexwpnas07_data01/18/2620618/html/wp-content/plugins/planso-forms/includes/form.php on line 476 “

I tried to:
– Deactivate and Activate the plugin
– Erase it and download it again
– Erase the 2 pages with the form and create 2 new pages and put the forms code again

Still nothing, still the same fatal error come out.

Have you guys have any suggestion?

I’m a total noob with all of this, learning while I’m using it how to use it…
Thanks in advance and sorry if my tech knowledge/vocabulary is not at you level.