proluse 9812b initial IO error (with Keithely 4200)

hello,

I am using a computer to control keithley 4200, propluse 9812B, and agilent 35670A to test the noise. An initial I/O error occurred during the test. When  propluse 9812B and  agilent 35670A are connected to 1500, the test is completely normal.The error is shown in the picture.