Fans of the underused and little-known technology mostly referred to as "external storage" have found themselves blocked from installing the Windows 10 May 2019 Update.
The problem, which has had users scratching their heads as to why devices such as their shiny new Microsoft Surface fondleslabs were choking on the update, can occur if USB storage or an SD card is plugged in.
Microsoft has delicately referred to the issue as "inappropriate drive assignment" in its support article on the matter, using the example of an external device mounted as G: in the existing configuration being reassigned as H:.
Yes, it is 2019 and an awful lot of software still depends on drive letters.
More worryingly, the software giant warned that the reassignment can also afflict internal drives.
As such the update has been blocked from installing, showing the dread "This PC can't be upgraded to Windows 10" if you have some external storage plugged in.
Really, really want the May 2019 Update right now? Unplug those devices and yank that SD card, and Microsoft reckons that this issue, at least, won't stop the update.
Redmond said the problem will be fixed in a servicing update (after all, those Windows 10 images are already on MSDN) and that similarly affected Windows Insiders will see the issue resolved in build 18887. Alas, new 20H1 builds are on hold until the team has dealt with the bug currently stopping some 19H1 users upgrading.
The Windows 10 May 2019 Update is still targeted for a wider rollout (beyond lucky MSDN subscribers and Windows Insiders on the Release Preview Ring) in late May. Unless, of course, a show-stopper or two crops up.
It might be worth getting that bungee cord tied good and tight. ®