Import data not working from .Net code using Zono dll

Import data not working from .Net code using Zono dll

Hello Support,
I'm trying to upload records in json/csv format using the zoho reports.dll but it seems is not working.
Here some code samples  

{code}
Dictionary<string, string> ImportRes = new Dictionary<string, string>();

// json in memory string doesn't work
        ImportRes = RepClient.ImportData(tableURI, ZohoReportsConstants.APPEND, {in memory json string}, ImportConfig);

// text file with json format doesn't work
        ImportRes = RepClient.ImportData(tableURI, ZohoReportsConstants.UPDATEADD, @"C:\json.txt", ImportConfig);

// text file with csv format doesn't work
        
        ImportRes = RepClient.ImportData(tableURI, ZohoReportsConstants.UPDATEADD, @"C:\commasepparatedfile.csv", ImportConfig);

{code}

ImportRes always returns nothing.

Help will be appreciated