Can neither use nor delete my Hana Trial Instance due to " peer not authenticated"

Status Metrics shows:

CRITICAL  - HANA XS Availability - JMX CRITICAL - Status.details = CRITICAL Internal Error: Hana XS  ... (peer not authenticated)

In eclipse i loose sometimes connection.

Delete also failed with:

Unable to delete trial instance 'trialinstance': Bad Request (400) - Error deleting DB user NEO_9OY31KSQCP4MAJNXL9HFXUR7H on DB instance Sid='JTF' , Url='jdbc:sap://vadbjtf.nwtrial.od.sap.biz:30015/': Could not remove certificate: Could not delete Certificate due to an internal error (Failed certificate removal for host [vadbjtf.nwtrial.od.sap.biz:8041 account[p1941120780trial package[trialinstance]) and had problems checking if certificate exists (peer not authenticated)

Means i cannot use my account anymore for XS app programming.

Can anyone help/reset ?

thanks in advance,

Mathias