On the support site it says the following:

http://terratec.ultron.info/Audio/EWS/64digit … B.htm#Frage%202:

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Question 2:

During boot-up the EWSINIT.EXE program reports the error '1st PCF8574 Write Failed'.

Answer 2:

Unfortunately, we must request you to contact our customer services. You can either do this by telephone
during our usual technical support hours or directly by e-mail.
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Has anyone ever heard about this or knows the response? I'm getting it unfortunately 🙁