Certificates with duplicate AIA extensions, from different CA’s (possibly different Intermediates from the same root CA).
From NetScaler 11.1 55.x and 12.0-53.x, a new security feature has been added to stop users adding Certificates with duplicate AIA extensions. When these are added to the NetScaler, it can cause OCSP Request failures for the OCSP Stapling feature and other security concerns.
This is being reviewed under issue ID 694395. The issue fixed in version in 11.1 55.13 or above and in 12.0 53.13 or above
This will not occur in NetScaler builds earlier to 11.1 55.x and 12.0-53.x.