I think I have a hunch as to what this is.
Some googling showed that this happens when you are trying to spawn more threads than your machine can handle.
From your previous post/discussions I understand this happens when you run the cdma_rx file.
The part of this program that generates a lot of threads is the aqcuisition filterbank
which we have made highly parallelized.
If this is the case then it should also happen running cdma_txrx (please try it).
Recall that gr-cdma is fully parameterized by the user.
So to fix this (this is not a bug, it is the feature of the system) try to change the variable
n_filt=51 to some smaller value (try 11).
I hope you understand what the tradeoffs are (reduced capability of receiver to handle frequency errors).