SSL Connection Error per REST API

I had a call with Niklas.

I'd be interested to hear if anyone else is having similar issues.  We currently think that the problem is elsewhere, but it'd be good to know if other people are suddenly also getting issues.

Hello
I do have the SSL error from today and my M-Files cloud is not migrated to the new Cloud yet

Can you give details on the error message?

There are a variety of reasons for this, but they all boil down to the client and server being unable to negotiate a protocol to use. If this is an existing application and vault then please raise a support ticket.  If this is a new application then you need to check the full error stack to see what is wrong; it's probable that you need to enable some newer protocol support somewhere.

I'll raise a ticket. The error is:

The SSL connection could not be established, see inner exception. The SSL connection could not be established, see inner exception. The remote certificate is invalid because of errors in the certificate chain: PartialChain 

I'll raise a ticket. The error is:

The SSL connection could not be established, see inner exception. The SSL connection could not be established, see inner exception. The remote certificate is invalid because of errors in the certificate chain: PartialChain 

So the issue is that your system cannot validate - or does not trust - one of the certificates in the chain.

Support may be able to guide you on whether there have been some changes.

Surprising to happen suddenly today while this API integration has been running fine for years now

Me too, but certificates do get changed on servers, and trusted certification authorities also change even in Windows.  You can often use a browser to take a look at the certification chain that's used, and maybe you can use that to cross-reference why your application doesn't trust a part of the chain any more.