Hey guys,
I'm currently trying to play around with the TinyDTLS package maintained by @rfuentess . However while trying to make it fly I often get the following errors on the node (dtls-echo):

RFCORE_ASSERT(len <= RFCORE_XREG_RXFIFOCNT) failed at line 91 in rfcore_read_fifo()!
RFCORE_SFR_RFERRF = 0x02

RFCORE_ASSERT(NOT(flags & RXUNDERF)) failed at line 40 in isr_rfcoreerr()!
RFCORE_SFR_RFERRF = 0x00

...

RFCORE_ASSERT(RFCORE_XREG_RXFIFOCNT > 0) failed at line 77 in rfcore_read_byte()!
RFCORE_SFR_RFERRF = 0x00

I'm using one CC2538DK with the gnrc_border_router image as a border router to access the second device.

Sometimes similar errors occur on the border router as well:

gnrc_uhcpc: uhcp_handle_prefix(): got same prefix again

RFCORE_ASSERT(RFCORE_XREG_RXFIFOCNT > 0) failed at line 77 in rfcore_read_byte()!
RFCORE_SFR_RFERRF = 0x02

RFCORE_ASSERT(NOT(flags & RXUNDERF)) failed at line 40 in isr_rfcoreerr()!

RFCORE_SFR_uhcp_client(): sending REQ...

The DTLS handshake doesn't happen in the end (my guess because of those errors). Any ideas?