All available licenses are assigned to other machines

Discussion
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I have already registered for 3 versions of Cinema 4D (R18, R19, R20). When I wanted to register for Cinema 4D R 21, a message appeared: “all available licenses are assigned to other machines”.
Is it possible to hit licenses on older versions of Cinema 4d without being able to use them later on on older versions of Cinema 4d?

I want to use Cinema 4D R 21.

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PM’ed the reply as it contains some personal information.

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