Microsoft said it has identified and fixed the problem.
If an IT shop's WSUS servers were synchronized with Microsoft's servers between 5 p.m. on Sunday and 11 a.m. on Monday, Pacific Standard Time, it would likely have had problems accessing the console.
The problem started when Microsoft renamed a product category entry for Forefront and put it in double quotes. A double quote is a restricted character in WSUS and therefore created an error in the administrative console, said Bobbie Harder, a Microsoft WSUS senior program manager on WSUS product team's blog today.
On Monday morning, Microsoft renamed the category to eliminate the double quotes, which should fix the issue automatically when IT managers next synchronize their WSUS servers with Microsoft's servers, Harder said.
If the console is not operational on WSUS 2.0, IT shops can force a manual synchronization by running a batch file. With WSUS 3.0, IT managers can force a manual synchronization through the WSUS configuration or "OOBE wizard," according to, Harder's post, which goes into further technical detail on both fixes.
Windows shops should not be affected by this issue if they did not synchronize their WSUS servers with Microsoft's before this problem was fixed on Monday, or chose to directly use Windows Update, Microsoft Update or automatic updates, which are not impacted by this error.