Certificate could not be validated

[David Woolley]

On 18/05/17 13:30, Evalee Gress wrote:
> Could this be due to a Microsoft update?
>
Most unlikely.  A Microsoft update might remove trust for a root 
certificate, but the error you are getting is that the certificate is 
expired.

> When I asked my IT dept. about this, they said they thought it might be due to a Microsoft update. Is that possible?
>

When it comes to security, IT departments shouldn't be guessing! 
However, if you are using the machine for the companies purposes, you 
can act on their advice to ignore the error, as it is the company's 
security that is at risk, so they have the right to decide when to 
ignore warnings.

Certificates have a limited life because of similar reasons to those for 
which credit and debit cards get replaced.  The longer a particular 
certificate is in use, the longer the bad guys have to break the 
encryption.  Also, flaws can be found in the methods used, and new 
certificates allow believed safer methods to be used; this has actually 
happened.

If the company doesn't need security for this application, beyond that 
which applies to the whole network, they should disable encryption, 
unless the server does not allow that.

> Other than that, they didn't know what could be causing the problem.

The problem is very clear.  They have failed to replace the server 
certificate before it expired.  I am definitely concerned that the IT 
department was unable to understand that error.