Windows Defender makes Opus unresponsive for a while in "download" folder

Hi,
for a while now, everytime when i click on the "downloads" windows library folder the program becomes unresponsive for about a minute. After that it shows the expected behaviour.
I don't have this problem with the default windows explorer.
What could cause this problem? Has anyone else this problem?

Does it still happen if you disable any realtime antivirus scanners?

They are probably blocking the process while they scan the downloads due to Opus looking at them to see if they are self-extracting zip archives. Opus will only be trying to read a tiny amount of data, but opening the files at all may cause an antivirus scanner do do a complex scan on the entire file. Some poor antivirus scanners (Microsoft's, in particular) will do this every time the files are accessed, without caching the result. (Good antivirus will avoid rescanning the same file again if it hasn't changed and the definitions don't require a rescan.)

That is usually the reason behind temporary freezes when viewing download folders.

Removing .exe from the list of Zip extensions (Preferences / Zip & Other Archives / Zip Files) and/or hiding Zips in the folder tree (Preferences / Folder Tree / Contents) can help to avoid triggering the problem, but the underlying issue is likely with the antivirus tool rather than Opus itself.

you were right! it is windows defender who is slowing the process. I guess 35 gb in my downloads folder doesnt make it faster :smiley:

thanks for your reply

Microsoft's antivirus is particularly bad in this regard. It seems to rescan large installers even when there is no reason to scan them again.

The first scan makes sense, and maybe again if relevant definitions have changed, but good antivirus will avoid scanning an unchanged file over and over each time something looks at it.