Sharepoint 2013 500 internal server error

That is a good step when you have that error. That is a somewhat generic error and can be caused by various different conditions. The next step however may be to restart IIS. If this is a multiple server, restart on each server unless you can isolate where the error is.

If that does not solve the problem, then take a look in the event viewer of each server to see if there are any errors that effect SharePoint. Let me know what you find.

Good luck...

I have restarted the Sharepoint server, and also it's database backend server.

After some more investigation, I have noticed a certificate installed on the Sharepoint server expired yesterday. Our sharepoint site became inaccessible today. I checked the bindings in IIS and didn't see this cert bound to any sites. Are certificates set somewhere in sharepoint admin?

Note: I am not a sharepoint admin and did not design this system so I am a bit clueless here on how these certs are used. Also note, we do not access our sharepoint site over 443 from clients. We use http only.

An expired certificate could cause the error. Did you start receiving the Internal Server Error about the same time that the certificate expired.

As far as certificates with Central Admin, it is possible that the site was setup to use a certificate, but highly unlikely.

Here is a list of common causes of SharePoint outages. These are not in any order, just a list of a few possibilities:

Full Disks on SQL server, data or transaction
Windows update causing unexpected restart
Lose of connection to DC
Virus Scanning conflicting with search crawls
VM losing host
Witness server shutting down (?)
Lose of connectivity
Server shutting down
SQL service restart
Errand code
ADFS Service Hung
Changes to SPN service account name in AD
App Pools crashing or being shut down
IIS restarts (temporary no access)
Installing farm solutions
people shutting down servers when they mean to log off
power failure
Windows update causing unexpected results
Password expiring on service account
Password change on service account

This is a screenshot from the Sharepoint server. It shows that our Sharepoint admin (whom no longer works here) updated them annually. I just don't know how to update this. I know how to generate a CSR, sign it with our CA, and import the signed cert. But I don't know what to do beyond that. Is that all I need to do? I imagine I have to bind it somewhere.

In IIS there is a site named "SharePoint Web Services". Check the binding there to see if the certificate for port 32844 is expired. If so, after you import the new certificate you should be able to bind to it in IIS.

Glad you got it fixed...

Found the solution myself.