One day, though I did not do any specific config level changes, I started getting lot of errors, items were not saving, publish was not happening. Same object reference errors on every single major operation on my sitecore instance.
I looked at the logs and see bunch of Coveo related errors, Yes, I had Coveo installed on this instance. I ran the diagnostic tool of Coveo and see bunch of services having issues. Even the indexing was broken. It seems Coveo patches on to lot of Item pipelines like save, publish, etc.,
To debug this, there are few common steps you need to do and for most cases below should work.
In my case, I was using Windows Credentials for Coveo services and I had changed my password. 😉
But, it could be other service related issues that could be causing it – So, the traditional magic steps are –
1. Ensure Coveo Diagnostic is all green
2. Go to Windows Services and ensure all Coveo services are up and running.
Note – Some times the services show up as running, but, infact they would be broken. When issues persist, try to stop and restart service after ensuring credentials are correct.
3. Tip – wait for few seconds before starting the service after you stop it
4. Re-index all Coveo Indexes
5. Check Diagnostics again to ensure
These steps should help most of issues specifically when everything is installed correctly initially.
As always Coveo first time install is always rough on newbies. But, slowly you will get good hang of it, once you know the components.