Hi @Thomas.Haindl ,
We have customers that have created new certificate with AS 6 and no issue.
Could you please share with us the steps you did when you created the new certificate with AS 6?
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In few cases with OPC UA connection issues we saw “BadSecurityChecksFailed”:
I found similar report and it was caused by outdated version of UAExpert client. Can you tell us what version do you have and maybe update client to the latest one?