Loading Sample error when certain keys are pressed

    When I press certain keys on the keyboard, the "Loading Sample set" screen pops up and GrandOrgue reverts back to the sample organ. Even when using the sample organ the same thing happens. It is the same keys but different keys on different manuals. This is my setup:

    two midi keyboards = MAudio Keystation 61, Roland JX3p
    computer - win 10, 8 GB ram,. Intel 7i processor. only 5 Gb of ram is in use when running GrandOrgue
    sample sets used = Kalvtrask Church extended, Pitea School of Music, Pitea positive organ

    I am able to used the keyboards on the Hauptwerk trial software without issues so the hardware doesn't seem to be the issue.

    Any ideas on the cause?

    Thanks,

    Eric J