Thank you for posting in Intel Communities.
Could you please provide us with the below details to investigate more on your issue?
1. The Base toolkit version.
2. The steps you followed in order to download oneAPI Base Toolkit.
Thanks & Regards
It seems like the "cstddef" file is missing from your system, you could try on a system that has that file.
As we have not heard back from you. This thread will no longer be monitored by Intel. If you need further assistance, please post a new question.
Thanks & Regards,