FPGA error -20023

Hello, 

I have a project reading in data in FPGA and transfering it to RT for processing. In GeophoneInput_Real Time.vi after the express filter vi I get an error -20023. I cannot find a way to fix it, I think it is a timing issue but nothing I have tried has fixed it. 

Any help would be greatly appriceated. 

Regards, 

Chris