Since I downloaded the Catalina 10.15.4 I cannot open attachments on my yahoo email using safari

You are welcome. Try another browser as a test.

Firefox        10.9 or higher.      https://www.mozilla.org/en-US/firefox/new/

Opera Browser        10.9 or higher.    https://www.opera.com/computer?gclid=CI7J466rh8wCFRNahgod1f4BNg

SeaMonkey      10.9 or higher8.     http://www.seamonkey-project.org/

Waterfox          10.8 or higher.     https://www.waterfox.net/download/

You can also try Safari Technology Preview. Go to Safari/Preferences/Advanced and check Show Develop menu in menu bar. Go to the Develop menu and select Get Safari Technology Preview. Open from the Applications folder.

Are you running any anti - virus programs? Using a VPN?

Try setting up another admin user account in System Preferences/Users & Groups to see if the same problem continues. Please post back on whether or not this worked. Also try the Safe Mode. Please post back on whether or not this worked.

Isolating an issue by using another user account    

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If you want to, you can send Apple feedback. They won't answer, but at least will know there is a problem or a suggestion for change. If enough people send feedback, it may get the problem/suggested change solved sooner.

Safari Feedback     

I have exactly the same problem. Not a lot of help from Sky as I access Yahoo through that service.

I have discovered that the attachment can be dragged to the desktop, clip on it and it will open. Personnaly not really interested in using another browser but it would be a nice idea if Apple and Yahoo talked to each other. Don't know about you but I am running Avast.

Regards

Many thanks for the reply - beginning to think I was paranoid. I'm not you understand the whole world and Yahoo are against me. Trying to get through to Yahoo otherwise know as the untouchable is 'difficult'. Two sides here need to talk to each other.

Problem with Catalina 10.15.4 for Mac OS update: AOL mail with Safari no longer works properly. The recipient of an email has trouble downloading an attachment. Instead of downloading it, the email window closes. Likewise, the recipient sees a question mark inside the insert box instead of an inserted picture. Sometimes while composing and using insert, you already get the box with the question mark in it.

I am reasonably sure the problem was caused by Safari with update 10.15.4 because AOL mail still works perfectly with Firefox and 10.15.4. How does one get Apple's attention that these updates are messing some things up? I've seen other complaints with the updates.

I have same problem with AOL mail.