Please Choose a Valid Email Field in Zoho Writer when started from CRM

Please Choose a Valid Email Field in Zoho Writer when started from CRM

Final step of
Create contacts, select all, Choose Template of Zoho Writer for Mail Merge.
Everything starts up right.
All fields are there and work fine.
Step 3 choose email and put in the Email field Contacts_email and the Email Subject.
Then it errors and says Please Choose a valid email Field.

What the Fark????

That is an email field.
Even setup as an email field in the setup->contacts field type.
Help??