Why am I getting a “From Name” validation error when saving settings?

Why am I getting a “From Name” validation error when saving settings?

The From Name field allows only specific characters. If you use an emoji, HTML code, or an unsupported symbol, the plugin will show a validation error and the email will not send. 
Make sure to remove any emojis, HTML tags, or special characters from the From Name and save the changes.
Allowed characters:
  1. Letters, numbers, spaces
  2. Symbols- . , _ - + & ’ ( ) :