Can't open .c4 files

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johnsmith88
Posts: 6
Joined: Tue Apr 18, 2023 1:26 pm

Can't open .c4 files

Post by johnsmith88 »

Hi folks,

I can't open .c4 (JEDMICS) files by double clicking on them. XnView just opens to the blank screen (or the Browser if you have that set to open on program start). The file opens if I go to File > Open, or by dragging the file icon onto XnView. It just doesn't open by double click. Likewise doesn't open by clicking links to .c4 files from a webpage. "Display all image file types" is enabled.

However, XnView MP works by double clicking the file. At least on this computer. But if I try it on another computer, neither Classic or MP can open on double click. So the problem is not really consistent. All other compatible filetypes open just fine.

Is this an XnView setting somewhere, or a Windows setting?

Thanks.
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xnview
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Re: Can't open .c4 files

Post by xnview »

do you have Settings>Display all file formats?
Pierre.
johnsmith88
Posts: 6
Joined: Tue Apr 18, 2023 1:26 pm

Re: Can't open .c4 files

Post by johnsmith88 »

Yes sir. I can open the file by dragging it onto XnView, or by using File > Open. But if I double click on the file, it just opens XnView to a blank screen.
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xnview
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Re: Can't open .c4 files

Post by xnview »

you need check the registry entry for .C4
Pierre.
johnsmith88
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Joined: Tue Apr 18, 2023 1:26 pm

Re: Can't open .c4 files

Post by johnsmith88 »

I thought it might have something to do with the registry. Any particular registry entry I should look at?
johnsmith88
Posts: 6
Joined: Tue Apr 18, 2023 1:26 pm

Re: Can't open .c4 files

Post by johnsmith88 »

Any idea what values I should change or delete in the registry? Thanks.
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xnview
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Re: Can't open .c4 files

Post by xnview »

johnsmith88 wrote: Tue May 02, 2023 3:05 pm Any idea what values I should change or delete in the registry? Thanks.
please check .c4 entry in HKCR
Pierre.
johnsmith88
Posts: 6
Joined: Tue Apr 18, 2023 1:26 pm

Re: Can't open .c4 files

Post by johnsmith88 »

Here is the entry for HKEY_CLASSES_ROOT\.C4
(Default) string with data C4_auto_file

Is this correct?
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xnview
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Re: Can't open .c4 files

Post by xnview »

and what do you have in C4_auto_file?
Pierre.
johnsmith88
Posts: 6
Joined: Tue Apr 18, 2023 1:26 pm

Re: Can't open .c4 files

Post by johnsmith88 »

I've been doing a little digging. Sorry for my ignorance. C4_auto_file appears several times in the registry. But I'm not really sure what to do with it. Attached is a screenshot of all the locations it appears. I'm not sure if you can gain any information from it. We might be at a dead end here. Thanks.

Code: Select all

Windows Registry Editor Version 5.00


[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428_Classes\C4_auto_file\shell\open\command]
""="\"C:\\Soft\\XnViewMP\\xnviewmp.exe\" \"%1\""

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428_Classes\.C4]
""="C4_auto_file"

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428_Classes\]
""="C4_auto_file"

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.C4\OpenWithProgids]
"C4_auto_file"=hex(0):

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428\SOFTWARE\Microsoft\Windows\CurrentVersion\ApplicationAssociationToasts]
"C4_auto_file_.C4"=dword:00000000

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428\SOFTWARE\Classes\C4_auto_file\shell\open\command]
""="\"C:\\Soft\\XnViewMP\\xnviewmp.exe\" \"%1\""

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428\SOFTWARE\Classes\.C4]
""="C4_auto_file"

[HKEY_USERS\S-1-5-21-4276474514-3336788208-196049622-361428\SOFTWARE\Classes\]
""="C4_auto_file"

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.C4\OpenWithProgids]
"C4_auto_file"=hex(0):

[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\ApplicationAssociationToasts]
"C4_auto_file_.C4"=dword:00000000

[HKEY_CURRENT_USER\SOFTWARE\Classes\C4_auto_file\shell\open\command]
""="\"C:\\Soft\\XnViewMP\\xnviewmp.exe\" \"%1\""

[HKEY_CURRENT_USER\SOFTWARE\Classes\.C4]
""="C4_auto_file"

[HKEY_CURRENT_USER\SOFTWARE\Classes\]
""="C4_auto_file"

[HKEY_CLASSES_ROOT\C4_auto_file\shell\open\command]
""="\"C:\\Soft\\XnViewMP\\xnviewmp.exe\" \"%1\""

[HKEY_CLASSES_ROOT\.C4]
""="C4_auto_file"

[HKEY_CLASSES_ROOT\]
""="C4_auto_file"
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