The Shibboleth Project has released a patch for the Identity Provider software primarily to address a security issue just announced previously, along with a few other bug fixes, including a UI regression impacting people using the initial authentication feature.
It is available from the download site now. 
With respect to this patch, please review the release notes  because you may be in a small minority of deployers for whom the patch requires a small additional step to keep your custom webflows functioning correctly. This change was unfortunately necessary as part of the mitigation of the security issue discovered. Basic functionality of the IdP will work regardless but any use of custom event handling for errors will require the additional bit of work.