“Something went wrong”

Hi,
I got help from you yesterday and it worked –> https://wordpress.org/support/topic/are-company-api-credentials-mandatory/

But today it doesn’t work again.
My WP install is a multisite. I activated the plugin on the network.
Yesterday, I was able to add a company and buttons to the main site.
Today, I tried on one of the subsites and I can’t add a company. I get the message “Something went wrong”. That’s all. No error code or anything.

Can you help?

The page I need help with: [log in to see the link]