Problem precisely described on Oracle website https://support.oracle.com/knowledge/Middleware/2338182_1.html with its solution doesn’t solve it in specific case.
I have created RCU schemas with OSB12C prefix. There were some other issues and I had to reinstall it.
I was trying to reinstall domain on the same RCU set but it failed. This forced me to re-create RCU, everything the same but Prefix was modified from OSB12C to OSB12, to exclude any kind of conflicts.
I moved back to OFM installer and tried to install new OSB domain on this new RCU setup but it failed every time when it was trying to pass OPSS Processing step.
It failed exactly with below details:

Error: CFGFWK-64254: Error occurred in "OPSS Processing" phase execution. 
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