Connection error between RFNoC and gnu radio blocks.

Hello,

I am using GNU radio 3.8 version, UHD 3.15, and Ubuntu 18.04. gr-ettus is built and the required FPGA image is built and flashed onto the USRP. But, when the blocks are used the connection between the gnu radio block and the rfnoc block is not working. The same issue is happening when I am trying to run any of the examples from the gr-ettus folder. The grc image is attached. A datatype mismatch is there between the blocks. How to solve this issue. Thanks in advance for any help.

Lakshmi