Library folder slow to load


Ever since with Opus v11 I have been having an annoying problem with viewing my download and document folders in the Library folder, it's takes almost a minute or two to show the content of that folder. Once it shows then it's normal but and here is what stranger when I leave either of those folders and go somewhere else (not in Library) and come back after a few minutes it's slow again. When using Windows Explorer I never have that problem. I just upgraded today to Opus v12 thinking that problem would be fixed but it's still there. When I look at the properites of download and document folders they just point to the user's download and document folders nothing else.

I hope someone has an answer to this problem.

BTW, these folders are on the local C: drive not on a network drive or NAS.


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If you go directly to the downloads or documents folders, without using the library, is it the same?

Based on the types of folders, it's probably something in the folders, such as large installer .exe files or archives, in turn with antivirus causing extreme slowdowns.

As an example, Microsoft's built-in antivirus causes this problem when requesting the icons for such files, and it has been a problem they have ignored for years. Doesn't happen with other antivirus, but just opening a large installer and reading one byte from it triggers a huge delay as the file is re-scanned in-depth, despite not having changed since the last time it was scanned.

Hi Leo,

No it doesn't, but here is what is strange when using Windows Explorer I do not have that problem why? and I don't remember having this problem when v11 first came out. I will try turning off the AntiVirus and see if that makes a difference.

I guess my concern is why is it only directory opus having this issue. I also have another 3rd party directory program and it doesn't have this problem too. Is there anything else i could check?

Another thing I mentioned before which may be important is that when using Opus and going directly (not Library) do user\username\Downloads or Documents it works fine super fast, it's something with Library.


There are many things that it could be.

Making a Process Monitor log of what happens and looking at which files/folders are being accessed during the delay, and the stack trace of the operations, may reveal the cause.

If you save a Process Monitor log in PML format, zip it and send it to me privately, I can look at it for you.

Ok i created the process monitor log, how do i send it to you privately? This is my first time on this board and I can't find how to do it.


Click my name or icon and there should be a Message button in the pop-up. (I think it should be enabled, although this forum software is new to me as well!)

Alternatively, you can email the zip to if that is easier.

Looking at the log file, the problem is almost certainly your anti-virus.

It is causing file-open (not reading any data, just opening the file before any data has been read) to take up to 4 seconds per file with the .exe installers in your downloads folder.

File-open operations on local drives normally take about 0.00004 seconds per file (from a quick look at my own machine, with similar files and NOD32 antivirus running).

So in a like-for-like comparison, your antivirus is making it take 100,000x as long as normal to open files.

It looks like there may be more than one antivirus installed (Microsoft's one, and Malwarebytes), which may not be a good idea in itself. The problem is probably caused by the Microsoft scanner, which is becoming notorious for this slowdown issue with installer exe files. People have complained about it for years and Microsoft do not seem interested in fixing it. (It doesn't just affect Opus, but it seems to avoid affecting Explorer. Typical of Microsoft, really. :))

Some additional information (please see my previous reply if you haven't already):

If you edit Preferences / Zip & Other Archives / Zip Files / Zip Extensions and remove .exe from the list, it may reduce the problem.

The antivirus scanner will still cause problems in other places, but that will reduce the number of times those files are being opened in this situation and may make things tolerable.

Finally, I found the solution to my problem. My Download Folder would take 10-15 seconds to load, a programs subfolder within the Download folder with many ZIP files would take even longer (up to 30 seconds).

Weirdly enough I added the .exe back in/out three times and it suddently worked even with .exe included.
Now I wouldn't post this if I wasn't sure this was just a coincidence.

I fired up my Surface Pro 4 (also running 12.4.0) and the exact same behaviour here. Removing .exe from ZIP extensions helped. Adding it back in one time made it slow again. Doing it two more times and suddenly it works.

Even though you may never reproduce this behaviour I thought I'd share this anyway.

That will be caused by your antivirus scanner.

I'm using the standard Windows Defender, PC running on Creators Update and Surface on the latest build before the Creators Update.
Any exclusion rule to add to Windows Defender to avoid this problem in the future?

Microsoft's antivirus is... not great... these days. (If you search a bit, you can find people complaining that it can cause lots of slowdowns in Explorer as well, when looking at folders with large installer exe and archive files.) It does not seem to cache results and will potentially block for a long time every time that kind of file is opened for any reason, even if it isn't being executed or extracted.

You wouldn't want to exclude those files completely as they do need to be scanned; the problem is it isn't intelligent about re-scanning them again and again even when nothing has changed. At least, that is my understanding.

I don't know if you can configure it to be better. I'd use something else instead, personally.

Issue started again, so for now I'm simply leaving out .exe from ZIP extensions. I can't see a difference functionality wise, what does this setting even do?

I won't change the Windows 10 standard antivirus as it has served me well and I don't need another company getting my data (Antivirus software can be quite intrusive) and even pay them for it.

It lets you treat self-extracting zip archives as zip archives that you can go inside or extract without running their executable parts. If you don't do that often then turning it off makes sense. (You can always open the files in 7-Zip or WinRar, etc. if you need to do it on rare occasions, while avoiding the slowdown in Opus which having it on all the time can cause when using Microsoft's antivirus.)