Hi Neha,
this is only a warning and no error. You can also check this forum entry: https://forum.mendix.com/link/space/connectors/questions/96546
For explanation I found this on stack overflow:
The warning indicates that you called close() without reading the whole file. This is problematic because S3 is still trying to send the data and you're leaving the connection in a sad state.
There's two options here:
Seems like you can’t really do anything about it except reporting this to Excel Importer.
Cheers,
Jan