Dremio IllegalStateException: Workspace variable 'value' in aggregation function 'single_value' is not allowed to have variable length type

Question

I have a query taken from an ERP application (using SQL Server) which i'm trying to translate into Dremio. It is simply unioning description field text (NVARCHAR, various lengths) from various views. How do I get past this error message in title? I've tried various things like CAST to VARCHAR in source views, in subqueries but nothing seems to work...

(CAST((
                 SELECT T.NAME
                 FROM DIMATTRIBUTEBANKACCOUNTTABLE T
                 WHERE T2.VIEWNAME = 'DimAttributeBankAccountTable'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEOMBUSINESSUNIT T
                 WHERE T2.VIEWNAME = 'DimAttributeOMBusinessUnit'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTECUSTGROUP T
                 WHERE T2.VIEWNAME = 'DimAttributeCustGroup'
                      AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTECUSTTABLE T
                 WHERE T2.VIEWNAME = 'DimAttributeCustTable'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEOMDEPARTMENT T
                 WHERE T2.VIEWNAME = 'DimAttributeOMDepartment'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEASSETGROUP T
                 WHERE T2.VIEWNAME = 'DimAttributeAssetGroup'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEASSETTABLE T
                 WHERE T2.VIEWNAME = 'DimAttributeAssetTable'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEASSETLEASELEASEDETAILS T
                 WHERE T2.VIEWNAME = 'DimAttributeAssetLeaseLeaseDetails'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTECOMPANYINFO T
                 WHERE T2.VIEWNAME = 'DimAttributeCompanyInfo'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEMAINACCOUNT T
                 WHERE T2.VIEWNAME = 'DimAttributeMainAccount'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEVENDGROUP T
                 WHERE T2.VIEWNAME = 'DimAttributeVendGroup'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEVENDTABLE T
                 WHERE T2.VIEWNAME = 'DimAttributeVendTable'
                       AND T.RECID = T1.ENTITYINSTANCE
                 UNION ALL
                 SELECT T.NAME
                 FROM DIMATTRIBUTEHCMWORKER T
                 WHERE T2.VIEWNAME = 'DimAttributeHcmWorker'
                       AND T.RECID = T1.ENTITYINSTANCE
             ) AS VARCHAR(60))
       )                          AS DESCRIPTION

Tried adding CAST(T.NAME AS VARCHAR(60)) to subqueries but hasn't resolved error.