The error occurs because of an incompatibility with the current EMS SSL. It afflicts all current hotfix levels of Substation ES 2.12.0
The appropriate library is available in Substation 2.12.1 hotfix 1, which can be installed in a substation ES 2.12.0 environment. Any future hotfixes for Substation v2.12.0 will include these changes.
Resolution
The problem can be rectified by downloading and installing Substation ES v2.12.1 hf#1 in your v2.12.0 environment.
Substation ES v2.12.0 must be updated to hotfix #4 before installing v2.12.1 hf#1.
Installing the hotfix will overwrite your SSL configuration. You can either note down your current settings and use the SSL panel to re-apply them after the installation, or follow the steps below.
Export your Config File (VSAM) using SXT3CFUT with your current software version
See <userhlq>.JCL(SXSCFEXP)
Apply Substation ES 2.12.1 HF001 to your system
After applying HF-001, rebuild Config File with SXT3CFUT using the exported data from step 1
See <userhlq>.JCL(SXSCFDEF) - defines new file See <userhlq>.JCL(SXSCFIMP) - import old data
This process will preserve all your Config File definitions especially ESB ones that use SSL
Issue/Introduction
SSL problems in Substation v2.12.0 can be resolved by instaling v2.12.1 hotfix 1