I think the only one you need to disable is the Column Handler, which won't affect the Preview Handler. It's this one if you're using ShellExView:
Alternatively, in Opus, adding {D8716A0E-4E9F-4D3F-BF1B-3460D86BB310} to Preferences / Miscellaneous / Advanced [Troubleshooting]: ignore_context_menus seems to be enough to fix things, at least from my quick testing.
(ignore_context_menus also blocks some non-context menu things these days.)
Leo, first, ignoring context works. Amazing. Second, big thank for your continuous support and unbelievable know-how.
Edit: The devs of XChange now noticed this issue, I'll report any news from their side.
Small question: The entry in "ignore_context_menus" won't be saved with prefs. On restore the entry is empty. Is this wanted?
It is saved. Check that your account has permission to write to this file/folder:
C:\ProgramData\GPSoftware\Directory Opus\Global Data\globalprefs.oxc
Yes, its stored in globalprefs.oxc, but the globalprefs.oxc not within DO-prefs-backup-file. After restoring Windows the old globalprefs.oxc (not including the context-value) was restored. So I wondered I had to enter the value again.
In Directory Opus 12.24 we have blocked the shell extension by default so you no longer have to.
I was in contact with TrackerSoft fixing this bug. I don't know, there was no update, but suddenly slow-down doesn't appear anymore. Can anybody confirm?
The column handler is blocked in Opus by default now (see the reply just before yours) so the problem wouldn't affect things unless you unblocked it or were using an older version.
We're talking to them to find a better fix so the column handler can be unblocked by default again.
I meant slowing down outside of DO! It does not appear anymore on my devices.
I think that's the first time anyone's mentioned it slowing things down outside of Opus in this thread.
If it's affecting more than just Opus then it might be best to talk about it on the PDF-XChange forum.
It also was slow on Windows' context menu after fresh start. As most usally use DO, they won't notice in Windows, Explorer,... itself. I noticed after it was blocked in DO.
But as it doesn't occur on 5 different devices here anymore - I just asked for others experience - my intention was to remove the fix in DO if also others confirm.
I don't know if that's the same issue or not.
Have you tried unblocking it in Opus and restarting? That'd tell you pretty quickly.
Yes, of course. Before you built in the fix I tried the manual fix in prefs and noticed it outside DO. Now its gone outside DO, that's why I reported it here again.
Edit: Bug seems to be gone with one of the last Win-Updates (and btw. never appeared on Win11).
I can't reproduce the problem either now, and it looks like the Column Handler shell extension has changed, which means the block would not be doing anything anyway.
PDF-XChange Columns Extension {D8716A0E-4E9F-4D3F-BF1B-3460D86BB310} is no longer there.
There's now:
PXCInfoShlExt Class {B2F55D43-C7A4-4B7C-90D7-7A860DFA9F2A}
Which doesn't seem to cause any problems on my test machine where I could see the problem before.
I am sorry to say that bug is not fixed... the desktop-context-menu is not affected, but when you click on an icon, delay appears. Reactivated issue at TrackerSoftware.
This is getting confusing, but I confirm that the issue still exists in some form.
I had not been seeing the problem recently.
I added {D8716A0E-4E9F-4D3F-BF1B-3460D86BB310} to Preferences / Miscellaneous / Advanced [Troubleshooting]: allow_context_menus and the problem came back.
I then disabled the PDF-XChange Columns Extension.
Problem remained.
Disabled PXCInfoShlExt Class.
Problem seemed to remain though without animation during pause before display.
Removed {D8716A0E-4E9F-4D3F-BF1B-3460D86BB310} from Preferences / Miscellaneous / Advanced [Troubleshooting]: allow_context_menus.
Problem gone.
Re-enabled both shell extensions.
Problem not evident (apparently masked by the block in Opus).
For whatever it's worth, I'm currently using PDF-XChange Editor Plus version 9.1 build 356.0.
I am also a user of PDF-XChange Editor Plus 9.1 Build 356.0
In addition to the problems stated above I have noted the following:
After starting my computer and then immediately starting Windows PowerShell in Admin mode it takes about 3 seconds to start however if I then close PowerShell and restart it the restart is instant.
I uninstalled PDF-Xchange Shell Extensions and the problem disappeared.
Tried to explain my problem to Tracker software but was a waste of time so for the past 2 months have just left Shell Extensions uninstalled as I never use them anyway.
Hope this helps
Nick
Also long time DO and PXE user here 
I'm seeing another slowdown which however affects the context (right click) menu on PDF files.
It can take up to a few seconds until that menu appears, and is particularly severe when using the menu for the first time after booting.
Could this be related to the shell extension problems that you guys have been discussing?
It could be, but it could also be due to another PDF shell extension on your system. The FAQ on right-click issues lists a couple of ways to diagnose which extension is slowing things down, if you want to investigate.
Thanks will do.
I also regularly clear unwanted things from the context menu using Nirsoft ShellExView, Nirsoft ShellMenuView, and recently Glary Utilities, the latter seeming to be particularly easy.
This is what I currently have in Windows Explorer, Dopus, and what is shown in Glary Utilities:
