My pc has suddenly stopped opening tumblr (just sits busy for ever) and some other sites like ebay too.
After much testing, I found that turning off Web Shield in Avast cured the problem…
Never had any problems with Avast before and I have been using it for years. No problems accessing website until yesterday morning.
Any ideas why this would suddenly happen?
OS…? (32/64 Bit…? - which SP/Build…?)
MS Vista 32bit SP1
Known issue on Vista. It should help to disable HTTPS scanning in the web shield.
Try just disabling the https scanning in the web shield settings.
This is an issue for many using XP and Vista, presumably avast are working on a fix.
I have only experienced this once on my XP system, I found that I could switch https scanning off, reload the page and then enable https scanning again. I don’t know if that would work for you also, as I don’t really like disabling https scanning as there are a huge number of sites now using https.
Thanks! Yes, turning off https scanning sorted it, but any ideas why this has just started (yesterday) after running 100% fine for however long since the last Avast update? (26th June I guess)
Please note that you need SP2 on Vista for the latest versions.
See: https://www.avast.com/faq.php?article=AVKB44#idt_100
Just put SP2 on but made no difference to the issue of https scanning stopping any pages with images on!
Yep, as it’s a known bug, but at least you updated your OS now. 
The SP2 issue is for greater compatibility/functionality with avast, not necessarily resolving this issue, which needs a fix from avast.
What surprises me is that avast even installed without having SP2 already installed.
In the meantime, I’ll try and get windows update to work! :
I just thought it was odd that a know issue would occur 2 days ago when Avast updated a week or two prior.
Are HTTPS threats a big problem?
The main issue is that many web sites are now using https protocols. Being a known issue doesn’t define how many would be involved.
That is why I would rather people tried only temporarily disabling https scanning and see if that works:
Today I had it happen on my XP system when trying to logon to my bank and did what I suggested in the last quoted paragraph above and that worked for me. So https scanning is still enabled.