limitation in the buffer allocation in visa set buffer VI in for the Virtual port if EKI-1524

HI all. 

I build test setup that contains network to serial server EKI-1524 from advantech and equipment coneected to it such as Scope, AC source and electronic load. 

Instrument driver of the scope for the downloading the screenshot allocates the receiving buffer for 1050000 bytes.

in this mode i receive the error  0xBFFF003C - insuficinet system recources.

I have checked this driver with USB to serial converter and with direct USB connection of scope - always work with no errors.

Checking the EKI-1524  virtual comport directly in max VISA TEST PANEL ( without instrument driver of scope  ) shows that maximum allocated buffer size is the 12288 bytes. 

Attempt to set the recevinig buffer size tp 12289 byte cause same error.

Please suggest how can i  fix this problem.