Shell extensions which are blocked by default

Extensions which are blocked by default

This is a list of third-party shell extensions which Opus tries to avoid loading, e.g. when generating right-click context menus.

Note that these extensions may still be loaded, and may still cause problems, unless you apply additional blocks system-wide (see below).

Each extension has a "CLSID", the long string in { }, which identifies it and can be used it you wish unblock it (see below).

  • Alcohol menu (x64) -- {AF67B665-D752-424E-9A03-C7C218F2844F}
  • Alcohol menu (x86) -- {32020A01-506E-484D-A2A8-BE3CF17601C3}
  • Bitcasa Infinite Storage menu -- {92224F8D-0235-4EBB-BEFB-91AC297C4AEE}
  • Bitcasa icon overlay -- {A6975448-A999-49BB-B3E4-7730CF6A82C0}
  • Bitcasa progress overlay -- {6FB8D52A-0064-45B2-B687-F596FEAD09C2}
  • File Renamer Turbo -- {7E3131FF-1322-22E5-9E3B-555664651111} as of Opus 12.17.1. This one cannot be unblocked as we had to block it at a very low level to avoid it causing problems and crashing other components.
  • LibreOffice columns -- {C52AF81D-F7A0-4AAB-8E87-F80A60CCD396}
  • LibreOffice infotips -- {087B3AE3-E237-4467-B8DB-5A38AB959AC9}
  • LibreOffice properties -- {AE424E85-F6DF-4910-A6A9-438797986431}
  • LibreOffice property sheet -- {63542C48-9552-494A-84F7-73AA6A7C99C1}
  • LibreOffice thumbnails -- {3B092F0C-7696-40E3-A80F-68D74DA84210}
  • Notepad++ -- Old ~2014 versions are blocked as of Opus 12.3.8. New versions are fine.
  • NVidia 'Play on My TV' menu #1 -- {FFB699E0-306A-11D3-8BD1-00104B6F7516}
  • NVidia 'Play on My TV' menu #2 -- {3D1975AF-48C6-4F8E-A182-AC5012248AB5}
  • NVidia Control Panel menu -- {3D1975AF-48C6-4F8E-A182-BE0E08FA86A9}
  • PCmag ContextMenuPlus -- {EECB3CFB-8757-11D3-9A66-00105A228F4A}
  • Qualcomm Atheros Commnucations Bluetooth Suite menu -- {B8952421-0E55-400B-94A6-FA858FC0A39F}

Prior to Opus 11.15.2, the extensions below were also blocked, but they are no longer blocked by default. If you have them installed and run into problems then it may be worth a try to block them and see if it helps:

  • Acronis True Image menu #1 -- {C539A15A-3AF9-4C92-B771-50CB78F5C751}
  • Acronis True Image menu #2 and property sheet -- {9E42900A-85F9-4E67-9778-575FBBA0A81C}
  • Acronis True Image icon overlay #1 -- {934BC6C0-FEC2-4DF5-A100-961DE2C8A0ED}
  • Acronis True Image icon overlay #2 -- {00F848DC-B1D4-4892-9C25-CAADC86A215D}
  • Acronis True Image icon overlay #3 -- {71573297-552E-46FC-BE3D-3DFAF88D47B7}

Why are some extensions blocked?

Extensions are added to the default block list if a pattern of problem reports is attributed to them over a long period of time and we are unable to find a better fix or workaround. (If there's only a one-off problem caused by a particular version of an extension, which is then fixed in an update, we'd be unlikely to add it to the list, except perhaps temporarily if needed to address a major issue affecting lots of people.)

We publish the list here so if you use one of the products involved you can know why some of its functionality (e.g. context menu items) may not appear within Opus. You can also override the list and make Opus load the extensions again, if you wish.

If an extension is on this list it only means that some of a program's functionality is disabled within Opus, not that all of it is. For example, a program's context menu items may be blocked while its extra columns and icon overlays remain.

Extensions not listed above may also be blocked automatically by Opus, only on your system (as part of your configuration), if Opus detects those extensions causing instability.

Problems may be the result of bugs in the extensions, and in those cases the same problems are often (but not always) seen in Windows Explorer and other programs. Problems may also be the result of extensions taking shortcuts or making invalid assumptions about the way they will be hosted which are not part of the API contract and which Opus does slightly differently (although we try to remove those differences when we become aware of them, to maximize compatibility). Of course, problems may also be the result of bugs in Opus and an extension being on this list does not necessarily mean the problem is in the extension itself; it just means the extension and Opus do not get on, we couldn't find anything wrong on our side, and we couldn't find a better workaround than blocking the extension.

Problems are not always crashes. For example, some context menu extensions cause long delays between you clicking and menus opening. If we find an extension which does that in the name of frivolous functionality, we may block it; if it's doing something useful then we'll probably leave it alone.

Generally, whatever the cause of the problem, we try to make things work. The list contains the exceptions where we couldn't find a way to do that.

Blocking extensions in more places

Opus's internal list of blocked extensions is only used in some places, since it is not always within our control which extensions are loaded. (In a lot of cases, Windows loads them itself when we do things like ask for the icon for a file.) The list also only affects Opus and not other programs, although bad shell extensions can cause problems outside of Opus as well.

You can use tools like ShellExView and AutoRuns to block extensions system-wide. Doing that will block them in more places within Opus and also block them from causing problems with other software on your computer. You may wish to do that with particularly problematic extensions (or even ones which just get in the way, slowing things down or cluttering up your menus with items you don't ever use).

Overriding Opus's blocked extensions list (Opus Pro only)

The list of blocked extensions is just our defaults and can be modified if you wish. You might want to see if an extension is still problematic, or you might even be part of the development team for a blocked extension and need to remove the block in order to debug the problem (let us know if we can help, and if it makes sense to remove the block in a future version). Alternatively, you might run into problems with an extension which is not on the list and wish to add it.

  • Adding extensions to the list (to block them):

    See the separate guide, Crash, exit or high CPU usage when right-clicking certain files

  • Removing extensions from the list (to unblock them):

    Go to Settings -> Preferences / Miscellaneous / Advanced, double-click allow_context_menus, then paste the CLSIDs (long string in curly-braces from the list above) of the extensions you wish to unblock, one per line, like this:

    Additionally, you may want to check the separate ignore_context_menus list to make sure the CLSID you want to unblock is not on that list. Opus may automatically block extensions by adding their CLSIDs to the ignore_context_menus list if it detects they have caused instability on your system.

    (Both allow_context_menus and ignore_context_menus start out empty by default.)

    You will need to restart Opus, as prompted, for changes to either list to fully take effect.

    Of course, if you then run into problems you should undo your changes to block the problematic extension again.