How can I avoid error - [Unable to combine data]...references other queries or steps...Please rebuil

Hi there,

2 weeks now i've been battling with this issue but can't find anything that will work despite multiple methods and workarounds.

I have a report that began life as a pbix. Worked fine when opening/running as that, but when published to the Service, will provide the following error when refreshing on demand or when scheduled:

Processing error[Unable to combine data] ............ references other queries or steps, so it may not directly access a data source. Please rebuild this data combination.

My report contains about 6 queries generally speaking. Each query gets data from one system. Method used is web API - Anonymous connection which I am using in Power Query. First a token is established from the system via API, followed by using that token with user's email and password and some other credentials to return responses. Each query of the 6 needs to return two tables - one for column id and name, the other table for content, and following steps merge these two tables to together to make one table that is loaded into the report for the data viz tools.

The query path/reference that this error indicates above leads to a query with just this simple line:

Get_columns = Json.Document(Web.Contents(#"loginUrl",#"logindata_COLUMNS (5)"))

loginurl is simply a parameter that contains the URI I am sending my API request to.

logindata_COLUMNS (5) contains the following code:

let


    logindata_COLUMNS=[
      Headers = [
        #"V-Locale"= "en-gb",
        #"V-TimeZone"= "Europe/London",
        #"Content-Type"="application/json;charset=UTF-8",
        #"V-Feature"="6",
        #"V-Token"=V_Get_Token,
        #"V-Organization"="9999",
        #"V-Email"=V_E
      ],
      RelativePath = "metadata/columns",
      Content=Text.ToBinary(V_logindata_body)
      ]
in
    logindata_COLUMNS

Some of these in logindata_COLUMNS (5) are linking to other steps (i.e. token) and referencing parameters. All which are functioning corretly - the token comes back fine and parameters should be fine to be called anywhere in a Service refreshing report.

Getting back to the first snippet where it is referncing to be the problem line - nothing else is containined in this query. It is just that line. I have tried adding everything together in one big query so it is not referencing anything else but the parameters, and conversely tried to separate each component into individual queries to break it up as much as possible into constiruent parts so that the call of the data is separated from steps that contain modifying the data in the table afterwards. Both approaches don't seem to get rid of this error which will identify some problem somewhere whether it's the line above or not.

What's the best practice here? How can I be certain that my report I'm creating on the desktop will work in the service? How can I be sure that this or any of these parts of the queries could work as a dataflow as well (it doesn't, I tried it as that too)?

I can't find much out there that tells you how you should specifically structure things in your reports to prevent these issues arising. So any help is appreciated.

License is Pro.