I use Google Sheets to house my data and recently had to update the Google Sheets connector following the Sisense version update.  As such, I can no longer update my model in the Desktop ECM and have very little experience working in the Web ECM.  I've had to reconnect all of my tables and basically rebuild the model, but I am running into an issue with a Custom Table that has worked to date as is.  

I am getting an error that the identifiers 'NamingConvention' and 'activitygroup' in Line 7 does not refer to a column, table or property...they do, but are clearly not being recognized (Sisense error bolded below) I am not great with programming and have been able to the model after 18 months of trial and error, but at this point I don't know what I don't know.  What am I missing?

SELECT DISTINCT
     A.NamingConvention
     ,A.activitygroup
     ,A.activity
     ,A.NamingConvention + '|' + A.activitygroup + '|' + A.Activity AS ActivityGroupKey
FROM (
     SELECT NamingConvention,activitygroup,activity
     FROM [Fact Hulu]
     Union
     SELECT NamingConvention,activitygroup,activity
     FROM [Fact Display]
     Union
     SELECT NamingConvention,activitygroup,activity
     FROM [Fact Programmatic Video]
) AS A

Please help, under deadline and this is the worst week ever for something like this to come up.

Thank you.