Survivors pension from Germany - what can be done when the marriage of the deceased and the claimant took place abroad, and a marriage certificate can't be found?

In this case, we advise to prepare a written declaration with the ​exact date of the marriage in the foreign country, and submit it to Rabbanut. The Rabbanut will issue for you a document stating that the widow/er gave testimony before the Rabbanut of the date of marriage.
This document stamped by the Rabbanut shall then be submitted to the Social Security of Germany in stead of a marriage certificate. This document doesn't need to be translated.