message queue error (Message to long)

Hi Community

I have trouble with message queue in Neutrino.

Everytime I start my programm with big Blocksizes > 3072 Byte

mq_attr.mq_msgsize = BLOCKSIZE;

an error is the Result -------> ( Message to long )

what’s the reason for this
and whats the reason in QNX4, it works perfect with BLOCKSIZE’s until
31 KByte

thank you