Error Prohibited input U+00000020

I had the same problem. This helped: I did NOT use the tool for "contact form" in pagebuilder, but the tool for "form builder" (below).

Yes, this is how it works, I have already seen this solution, but this is not solving, it is only circumventing the problem

I received this error also, and i believe it may possibly have something to do with the way the email headers are set up.

e.g.

Reply-To: {{email}}

Reply-name: {first-name}} {{last-name}}

Cc: {{email}}

I had changed the {{email}} in the form and also in the email template to be {{primary-email}}
Once i gave in and changed the form element name back to just "email", adjusted it to be the same also in the email template {{email}} things seemed to work for me.

Maybe this is a clue at least.

I get the same error message even filled in all require fiels

Prohibited input U+00000020

Joomshaper can you help?

Joomshaper can you help? it could be a problem of version 3.8.8?

I tried but I get the same result, I filled in the fields as figure but nothing ... in the end I gave up and used another component :(

I got the same error: Prohibited input U+00000020
Don't use the old form, rebuilding a new one will work fine.