Due to a problem with someone here at the University (not in our department) downloading too much content from MathSciNet, direct access to http://www.ams.org/mathscinet was requesting a “username and password”
(which we don’t have) for MathSciNet Authentication, when searches were attempted from departmental machines. If one tried to “Cancel” the connection then messages such as “MathSciNet Access Error” and “MathSciNet is available by subscription only” were displayed.
Work is underway to restore the direct access (in fact things appear to be working again at this moment) but in any case the access through the University’s Library URL:
still works as usual. You may want to bookmark this URL in case the problem recurs over the break.