Can't create contact due to "invalid property value"

Smart CRM & Sales Hub CRM
1

I keep getting this error message when trying to add a contact:

“The contact could not be created because of an invalid property value”

All I am entering is the first and last name, and an email address. The fields are all default single-line text fields, and all the info I am entering is correct. Other users in my company are having the same issue. What’s going on?

2

Like wise. This is new to me.

3

Why hasn’t anyone answered this?

4

I don’t know about you guys, but for me it was because I was copy/pasting an email address with a preceding space.