Lookup function in email builder returning error "invalid field" and does not pull data

I am trying to pull first name of a contact to my email (emailbuilder) through a simple lookup on my shared data extension.

<div style="display:none"> %%[  var @dataExtension, @returnedField, @whereCol, @whereValue  Set @dataExtension = 'ENT.Gaia Contact' Set @returnedField = '[First Name]' Set @whereCol = '[Contact Key]' Set @whereValue = OKID  Set @fieldValue = Lookup(@dataExtension, @returnedField, @whereCol, @whereValue)  ]%%</div>%%=v(@returnedfield)=%%

Looking to return a customer "First Name" from shared "Gaia Contact" data extension.Where to lookup the name I am trying to match "OKID" (variable in the emails active sending DE) to "Contact Key"(from the DE "Gaia Contact")

Yes, both the data extension and the objects have a space in them.

At the moment when I go to preview the email I get the following message:

It seems that the object is not in the DE, but if I open the DE I can see them both first name and the contact key.Also I confirmed manualy that the OKID have a match on contact key and does have the value for First Name in the mentioned DE(Gaia Contact).

Thanks in advance for any help.