I have had a MiKTeX installation on this computer for several years and it has worked mostly smoothly. However, since today, when trying to install new packages using the package manager I get the following error:

MiKTeX Problem Report
Message: Unsupported protocol
Source: Libraries\MiKTeX\PackageManager\CurlWebSession.cpp
Line: 402
MiKTeX: 2.9
OS: Microsoft Windows 7 Business Edition, 64-bit Service Pack 1 (build 7601)
Invokers: non-existing/explorer
SystemAdmin: no
PowerUser: no
Root0: C:\Users\JonasAdler\AppData\Roaming\MiKTeX\2.9
Root1: C:\Users\JonasAdler\AppData\Local\MiKTeX\2.9
Root2: C:\ProgramData\MiKTeX\2.9
Root3: E:\Program Files (x86)\MiKTeX 2.9
UserInstall: C:\Users\JonasAdler\AppData\Roaming\MiKTeX\2.9
UserConfig: C:\Users\JonasAdler\AppData\Roaming\MiKTeX\2.9
UserData: C:\Users\JonasAdler\AppData\Local\MiKTeX\2.9
CommonInstall: E:\Program Files (x86)\MiKTeX 2.9
CommonConfig: C:\ProgramData\MiKTeX\2.9
CommonData: C:\ProgramData\MiKTeX\2.9

I can still run MiKTeX as usual, i.e. build documents etc, but any attempt to install new packages gives this error message.

In addition, If i try to change my remote package repository, I get this very cryptic list of repositories:

Package manager screenshot

I have, to the best of my knowledge, not changed anything with the MikTeX installation myself since the last time I successfully used MiKTeX.

Edit: I have now encountered this problem on 3 of my windows machines, including 2 with windows 7 and one with windows 10. They all get the exact same error message and were all working just a few days ago.

  • 2
    Works fine for me on windows 10. Did you check for updates (as admin and as user)? Jul 5, 2017 at 11:50
  • 1
    I have similar problems with MiKTeX and see the same cryptic repository list in the package manager. I have this issue on two different computers.
    – wheeler
    Jul 5, 2017 at 12:35
  • 1
    @UlrikeFischer As indicated in the post, I have tried checking for updates but cannot find any repository when manually checking. If i try to use "Use the nearest package repository" I get the same message as above, e.g. "Sorry something went wrong, unsupported protocol" Jul 5, 2017 at 13:04
  • Do you have a multiuser installation? Did you try the admin version of the tool? And when was the last time that you did an update (admin)? Jul 5, 2017 at 14:19
  • It is a multiuser installation and I have tried with the admin tool (and without). The last time was perhaps a few months ago. Jul 5, 2017 at 14:39

2 Answers 2


Apparently, it was a bug on the server side and the maintainer (Christian Schenk) has fixed it. Should work now (it does on my machine without the need to reinstall anything) https://sourceforge.net/p/miktex/bugs/2609/


As mentioned in the comments, I also had this cryptic entry in the package manager repository list. I solved this by completely removing MiKTeX and reinstalling it (non multi-user). Now I get a full list of repositories.

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