UHD Got error code 0x4, exiting loop


I got this error, code 0x4, and I checked that it means “broken chain”.
Can anyone give me any more details? Why do I run into this error?

I am doing correlation of received signal. When I set the number of
received samples to be 20e6, it works fine. But if I increase the number
to be 80e6, this error will come out.

Thanks in advance.