I believe this behavior started about 6 months ago. Earlier the 'Save as' folder tree opened in last saved location, I think even different last saved locations relative to what site I downloaded from. Now the 'Save as' folder tree always opens in default location set in settings.

What decides this behavior (Opera settings? windows settings?), and how can I get the previous behavior described?

OS : Windows 7.
Opera : ver 47

Google image search with Opera displays 12 images, while with Firefox (useragent switch addon), it displays 36.

Opera: http://i.imgur.com/6lcjh9f.png
Firefox: http://i.imgur.com/Rau16Y1.jpg

Hence, I can't browse without a useragent switch..

Whats the reason for this difference?

I have same problem. Described here:
https://forums.opera.com/topic/20335/your-computer-is-low-on-memory-opera-using-6gb/1

Rather quickly, within an hour or two, grows from 1.8GB to 7.5GB+, and sometimes trigger windows "low on memory" warning.

(Windows 7, 64 bit)

Can't remember when it started, some time last year maybe. And on multiple computers(2) and installations(4), all running Windows 7 64 bit.

How can I reduce Opera's memory usage?

Opera is always rather quickly maxing out my memory, taking it from <2GB to ~7.5GB (8GB installed). And even triggering windows error "low on memory" message.

Yes I do use two windows and many tabs (100+ usually), but that's not really required to cause memory to max out.

low on memory error:
http://i.imgur.com/Lusycuq.png

Closing and restarting Opera: 7.5GB - 1.8GB - 3.2GB.
http://i.imgur.com/ZmZg31T.png

Addons installed:
http://i.imgur.com/XjZjz1o.png

So 1.4GB already after Opera restart, before any interaction. Well, that's not really a problem, but growing to 7.5GB+ is..

Any settings that can prevent this behavior..?

Have you tried with extensions disabled?

Seems to work with Google Translator disabled.

That PDF works fine here. Can you open it in a private window?

Did open in private yes. Enabling Google Translator option for private window made it not work there either.

Thanks!

How can I get an 'Open file' dialog, or preferably, an 'Open/Save/Cancel' dialog, like this one from Opera@USB 12.18:

http://i.imgur.com/lHuwVNJ.png

While I have problems displaying some PDFs, described here:
https://forums.opera.com/topic/16402/solved-opening-pdf-shows-black-page-not-loading/1

..I tried disabling the 'Chrome PDF Viewer' plugin.

This results only in a 'Save as' dialog for PDFs.

Version: 38.0.2220.41 - Opera is up to date, Update stream: Stable, System: Windows 7 64-bit (WoW64)

Many PDFs (not all) do not even attempt to load, displaying a totally black page.

Example:

http://imgur.com/a/DnqNs

https://www.uscis.gov/sites/default/files/files/form/i-864.pdf

What may cause this..?

Version: 38.0.2220.41 - Opera is up to date,
Update stream: Stable,
System: Windows 7 64-bit (WoW64)