When i try to validate the following page in the post inspector: https://www.cicomcopier.nl/nieuws/cicom-copier-levert-bijdrage-aan-de-ontwikkeling-en-realisatie-van-bellenschermen-tegen-verzilting-a-dam-rijnkanaal-en-noordzeekanaal/
I get the error: We encountered a server error while trying to inspect the URL.
and on the URL redirect trail i get: 0 undefined
I have no idea where to start debug this, is this a error on our side or linkedin side? when i debug the URL using the facebook graph debugger everything seems to be right.
The problem in the end was the server from where I did the request wasn't setup correctly. Because from my side the site had a ssl installed and needed to do a ssl handshake with the LinkedIn server.
LinkedIn is made in java, and java has a more strict policy in validating the handshake. Because from my server setting the hostname for the ssl was not communicated correctly to LinkedIn there server did not validate the ssl and therefore could not connect to our server and receive a response. This ending in a unknown error on LinkedIn end of the site.