sapmnt is missing after update - StartSystem occurs error NIECONN_REFUSED - What to do?

Hi,

in the end of December we had an update of our systems (BW/4HANA 2.0 to BW/4HANA2021, BW 7.5 to SP22).

The HANA DB and kernel was updated too.

Since December we hadn't had the situation to restart an instance. On friday we had.

Result: all instances are down and cannot be restarted. (HANA DB is still running without issues)

When I try to start a system with sapcontrol I get the following:

sapcontrol -nr 00 -host btsapserv -function StartSystem
15.02.2022 11:55:42
StartSystem
FAIL: NIECONN_REFUSED (Connection refused), NiRawConnect failed in plugin_fopen()

All SAP Notes related to NIECONN_REFUSED didn't help so far.

I think I is a problem because of the deleted sapmnt.

What do I have to do to get the systems working again?

Would be nice if somebody can help me.

Thanks and best Regards,

Alex