I tested this on two separate sites that are hosted by two completely separate companies, so there was zero chance of anything hardware related. Both sites are running 9.0.15 and both generate the same error.
When using the website cleanup tools, all work fine with the exception of:
If that option is selected either alone or in combination with others, both sites return this result:
An error has occurred
Unfortunately a query has failed [UPDATE ocp_f_members SET m_cache_warnings=0 WHERE (id=1 AND w_is_warning=1) LIMIT 1] [Unknown column 'w_is_warning' in 'where clause'] (version: 9.0.15, PHP version: 5.3.29, URL: /adminzone/index.php?page=admin_cleanup&type=rebuild)
Here is the stack trace:
Below is a stack trace revealing the state the software was in when the error occurred. If this represents a bug in the unmodified software, you may want to check ocPortal website for a fix, and if there isn't one, report this as a bug. Please note that merely posting a stack trace is not sufficient for us to solve your problem; the stack trace is just an aid that presents us with additional information. We still need to know the error message, what you tried to do, how you tried to do it, version numbers, and any other appropriate information.
We apologise for this problem and if it's a bug we hope you will work with us so that we can fix it for you promptly.
If not, please let us know how we can do better (please try and propose any bigger ideas in such a way that they are fundable and scalable).
If so, please let others know about ocPortal whenever you see the opportunity.
If my reply is too Vulcan or expressed too much in business-strategy terms, and not particularly personal, I apologise. As a company & project maintainer, time is very limited to me, so usually when I write a reply I try and make it generic advice to all readers. I'm also naturally a joined-up thinker, so I always express my thoughts in combined business and technical terms. I recognise not everyone likes that, don't let my Vulcan-thinking stop you enjoying ocPortal on fun personal projects.
If my response can inspire a community tutorial, that's a great way of giving back to the project as a user.