ABAP PROXY error on PO 7.4

hello everybody,

we are working with a PO 7.4 (only java) and we are tring to implement a SAP (ecc5) -> PO -> JDBC interface unsing ABAP proxy.

We configured ABAP proxies following this link:

Michal's PI tips: How do you activate ABAP Proxies with AEX - simplified version

the connection is ok and from SPROXY transaction we can see the SI interfaces made in PO.

When we try to use the proxy we have a dump:

we tried to launch SLDCHECK and we have this error:

and testing the definition in SLDAPICUST we have this:

we also tried to create SAPSLDAPI and LCRSAPRFC connection, but we not solved the problem

any suggestion?

best regards

Alessandro