It's been a banner month for Microsoft patches. Adding to the three I mentioned earlier this week, there's now a fourth confirmed bad patch, KB 2844286, part of the July Black Tuesday MS13-052 security bulletin, which is the .Net 3.5.1 patch du jour for Windows 7 SP1 and Server 2008 R2 SP1. If you install KB 2844286 on a system running SharePoint 2010, it will start generating random reports that say:

Unable to display this Web Part. To troubleshoot the problem, open this Web page in a Microsoft SharePoint Foundation-compatible HTML editor such as Microsoft SharePoint Designer. If the problem persists, contact your Web server administrator.

Web server administrators have been scratching their heads. SharePoint admin Tom Chucker has a full rundown of the cause and the cure on his website:

It appears the error typically appears when a list or web part view has had the XSLT customized. At least in our Farm, that has been the common behavior. As a temporary workaround, we found uninstalling the update (KB2844286) from your servers (all WFEs and App servers) then performing an IISReset on the servers will resolve the issue. Several others have experienced this issue

As usual, Microsoft hasn't acknowledged the problem in the KB article, although Chucker says, "Microsoft is aware of 2 issues regarding the patch noted in this article above. One of which appears to be the SharePoint issue we're having."

Microsoft is tracking the problem on the TechNet forum.

This story, "One more botched Microsoft 'Black Tuesday' patch: KB 2844286 ," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest developments in business technology news, follow InfoWorld.com on Twitter.