Troubleshooting Error -38 and Other Error Messages

Error -38 is a general communication error message. The following troubleshooting steps are recommended:

  • If you have more than one Thunderbolt Apollo or Satellite, verify they are daisy-chained from a single Thunderbolt port of your computer.

    Apollos share clocking over Thunderbolt, so it is critical they are connected in this manner. It is required that every UA Thunderbolt device is daisy-chained from a single Thunderbolt port. Please refer to the following example diagram:

    1_Error38_DaisyChain.png
    Refer to the Apollo & Satellite Data Cable Guide for cable specifications.


  • Error -38 and other error messages can be caused by a failing or faulty cable or adapter.

    It's not critical where a Satellite is placed in the chain.  Use a qualified Thunderbolt 2-3 adapter as needed. If you have another device on the same Thunderbolt bus as your Apollo, such as a Thunderbolt dock, it is recommended to move that to a different Thunderbolt bus for troubleshooting purposes.  You cannot exceed six Thunderbolt devices of any kind on a Thunderbolt bus.

  • If you have a computer with an Intel processor, make sure you follow the recommended boot order:
    1. Turn all devices off.
    2. Power computer, and allow it to boot fully.
    3. Power the UA Thunderbolt devices on, and allow them time to connect properly.
    4. Launch your DAW, and re-test.

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