SAMP does not really handle Nulls too well

The current SAMP implementation tries to convert the result items to strings, but if those are null, the conversion fails.

This one is easy to reproduce: open TOPCAT Go to the menu VO -> Table Access Protocol(TAP) Query (use obscore as keyword; I picked GAVO DC TAP) use select top 2 * from ivoa.obscore as a query and run it Register ESAP to SAMP and broadcast from TOPCAT: This will fail Edit the table in TOPCAT and replace all empty fields by your favourite value (yeah, bit of manual work) Now broadcasting works :)