It is not so rare to face the "Error while creating PSE" (TRUST040) when trying to create SNC SAPCryptolib PSE in SAP Netweaver AS ABAP environment. This might happen due to old corrections (check SAP Notes 1740744, 1756908 and 2198198). However, these corrections are not the most common cause for this error.
It is not so rare to find customers facing this error because their environment is not configured to use SAPCryptolib or CommonCryptoLib as SNC product, then the "Error while creating PSE" (TRUST040) when trying to create SNC SAPCryptolib PSE is expected/correct.
Customers can verify the SNC product configured in their environment by checking the parameter snc/gssapi_lib. The most common scenario is having it set to Kerberos library and, in such case, the SNC PSE won't be possible to be created, since Kerberos library does not use SNC SAPCryptolib PSE.
In other words... What is important to remember is:
=> If customer's environment does not use SAPCryptolib or CommonCryptolib as SNC product, there is no need to maintain the SNC SAPCrytpolib PSE. The name "SNC SAPCrytpolib PSE" already indicates that this PSE only has to be (and can be) created when SAPCrytpolib or CommonCryptoLib is used for SNC. Using Kerberos libraries or other external SNC products do not require such PSE.