Troubleshooting

Use the Codec Tweak Tool to disable the DirectShow filters and codecs that were installed by the pack. Disable one or a few at a time, until the problem is gone. That should make you able to figure out which item is the culprit.

Please also report the problem to us. Then that information can be added to this FAQ, or a solution can be devised to fix, prevent or workaround the problem.

For example, some of the included codecs have a blacklist feature that can be used to prevent those codecs from being used by specific applications. This is often an effective solution for compatibility problems that are the fault of other applications. See below on this page how to use the blacklist feature.

If your problem continues after disabling all components from the codec pack, or even after uninstalling it, then it is extremely unlikely that your problem is caused by the codec pack. Visit our support forum to get help with finding the real cause.

You can do that in several ways.

Media Player Classic: While playing a file, click on 'Play' in the top menu, then move your mouse onto 'Filters' in the drop down menu.

GraphStudioNext: Start GraphStudioNext. Drag and drop a file into the window. A graph will be build showing all filters that are used to play the file.

ZoomPlayer: While playing a file, right-click on ZoomPlayer. In the menu that appears, click on 'Filter Properties', then on 'Graph Information'.

BS.Player: While playing a file, right-click on BS.Player. In the menu that appears, click on 'options', then on 'Filters'.

Codec Tweak Tool > Generate Log

This creates a detailed log of all installed DirectShow filters and VFW/ACM codecs. It will also include some details about your hardware and drivers.

Codec Tweak Tool > Fixes

Then select the two options to detect broken codecs and DirectShow filters. If the tool detects something that is broken, it will prompt you with the details and you will be given the option to remove the broken item.

You can do this in several ways.

Codec Tweak Tool:

Run the Codec Tweak Tool that is included with the K-Lite Codec Pack. It has the ability to disable a large number of commonly used DirectShow filters ("DirectShow Filter Management").

GraphStudioNext:

Menu > Graph > Insert Filter > select the filter and click on "unregister".

Manually:

To manually disable a filter from the command-line use:

Start -> Run -> type: regsvr32 /u example.ax and press enter

If the file is located outside the Windows system32 folder, then you need to use the full path of the file instead of just the filename. If the path contains spaces, then surround it with quotes. For example:
regsvr32 /u "c:\program files\ac3filter\ac3filter.ax"

Some notes:

If unregistering fails, it usually is because the file is no longer exists on your system, but it's information is still present the Windows Registry. The Codec Tweak Tool that is included with the K-Lite Codec Pack has the ability to scan for broken filters and remove the leftovers from the Registry.

If unregistering succeeds, then the filter is disabled and it won't be used anymore. The file itself must be removed manually.

Be careful what you remove. Don't simply remove everything. A lot of filters are standard components of Windows or DirectX (e.g. quartz.dll). Don't remove those. If you are unsure, then right-click on the file (in Windows Explorer) and select properties. If is says anything about Microsoft Windows or DirectX in the properties, then you shouldn't touch it.

You can do this in several ways.

Codec Tweak Tool:

Run the codec tweak tool that is included with the K-Lite Codec Pack. It has the ability to disable the most common ACM codecs ("Codec Management").

Manually:

Go to the Windows Control Panel (Start > Settings > Control Panel) and double-click on 'System' to go to the System Properties.

Click on the 'Hardware' tab, then on the 'Device manager' button. Open 'Sound, video and game controllers'. Right-click on 'Audio Codecs' and select 'Properties'. On the properties tab you can remove audio codecs.

Some notes:

Be careful what you remove. Don't simply remove everything. Some codecs are standard components of Windows or DirectX. Don't remove those. If you are unsure what to do, we advice you not to touch anything.

You can do this in several ways.

Codec Tweak Tool:

Run the codec tweak tool that is included with the K-Lite Codec Pack. It has the ability to disable the most common VFW codecs ("Codec Management").

Manually:

Go to the Windows Control Panel (Start > Settings > Control Panel) and double-click on 'System' to go to the System Properties.

Click on the 'Hardware' tab, then on the 'Device manager' button. Open 'Sound, video and game controllers'. Right-click on 'Video Codecs' and select 'Properties'. On the properties tab you can remove video codecs.

Some notes:

Be careful what you remove. Don't simply remove everything. Some codecs are standard components of Windows or DirectX. Don't remove those. If you are unsure what to do, we advice you not to touch anything.

Some of the codecs in the K-Lite Codec Pack have a blacklisting feature that can be used to prevent those codecs from being used by specific applications.

If blacklisting solves your problem, then please report it to us, so that we can add the application to the default blacklist.

LAV Video Decoder

The blacklist is located in this Registry key on 32-bit systems:
HKEY_LOCAL_MACHINE\SOFTWARE\LAV\Video\Blacklist
And this one on 64-bit systems:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\LAV\Video\Blacklist

You can access the Windows Registry with regedit.exe tool from Windows.

You can add an application to the LAV blacklist by adding a new DWORD value to the above key with the filename of that application, and value 1.

LAV Audio Decoder

Similar to above.

LAV Splitter

Similar to above.

Important note:
The blacklist does not work if the splitter is forced as the default source filter for a specific extension. You can check if the splitter is forced as default by looking at these Registry keys:
HKEY_CLASSES_ROOT\Media Type\Extensions
HKEY_CLASSES_ROOT\Wow6432Node\Media Type\Extensions

When a subkey contain the valuename "Source Filter" with value "{B98D13E7-55DB-4385-A33D-09FD1BA26338}", then LAV Splitter is set as the default splitter for that file extension.

You can safely remove the subkey to make the blacklist functional. LAV Splitter will still be used by other applications (players) as long as there is no other splitter installed that has a higher merit.

ffdshow video decoder

Go to ffdshow video decoder configuration. Click on "DirectShow Control". Enable the box in front of "Don't use ffdshow in:". Then click on the Edit button behind it. Add the filename of your application to the list and then click on OK.

ffdshow video decoder

Similar as for ffdshow video decoder.

DirectVobSub / VSFilter

This filter has an internal blacklist. You can't edit that yourself, but the developers of the K-Lite Codec Pack can add new application to that blacklist.
You can disable DirectVobSub with the Codec Tweak Tool if you need to test if it is the cause of your problem.
Codec Tweak Tool > Codec and Filter Management > DirectShow