I invoked the miner via the command ./xdag -m -7 -d 52.5.32.68:13654
-7 is too many CPU threads.
But actually it is a bug.
Correct line:
$ ./xdag -m 7 -d 52.5.32.68:13654
lol - well that fixed it and one could argue that "-7" threads is too few

... (for those looking for the difference, you dont need the "-" on the CPU threads number)