What you are asking is to use the base_url token in views header. Views heade...

What you are asking is to use the base_url token in views header. Views header replaces the token by data from the first row. Since there are no rows, it is not supposed to work. The base_url token works same as Global: Custom text field, or any other global fields.

If you want to get the base_url token in header, there should be a views header field for base_url. There is a patch #2842587-3: Add header field plugin for base_url here that does the job, you can use it.