Why the new version displays previews in bad quality???

Could you please post the screenshot?

Websites are overblown, fuzzy, out of focus.The weather GIFS are not overblown, but they are rendered poorly.

In addition, 7 thru 9 thumbnails continuously clock. 7 is a local html file. 8 is npr.org. 9 is another weather GIF.

Firefox 56.0 (64 bit)

Can you post URLs of those dials?

1. https://finance.google.com/finance
2. http://cnn.com
3. h ttp://images.intellicast.com/WxImages/RadarLoop/pie_None_anim.gif
4. http://whatismyv6.com/
5. https://www.news4jax.com/
6. h ttp://images.intellicast.com/WxImages/RadarLoop/usa_None_anim.gif
7. file:///C:/Users/removed/OneDrive/Weather/WeatherInfo.html
8. http://www.npr.org
9. h ttp://images.intellicast.com/WxImages/SatelliteLoop/hiatlsat_None_anim.gif

Broke http for the GIFs so they wouldn't load here.

Also found the Speed Dial new version Intro window will pop occasionally and afterward the thumbnails become overblown and skewed. Doing a Refresh All (which continuously clocks all thumbnails), then quitting and restarting Firefox will put them back the way they were as shown above. BTW, dials 7-9 display when this happens but clocks again after the Refresh All and Firefox restart. Search is disabled in settings and the icon does not appear when this happens.

Also please note:

We got many error reports, rolled back to the previous version. Just reinstall the extension.
https://addons.mozilla.org/en-US/firefox/addon/fvd-speed-dial/

Once we finish fixing major problems, we will launch a new update. Most likely you will have the same problem again.
You will need to do following:
Option #1 #2 or #3
https://everhelper.me/help1.php

Unfortunately, you can't keep older version for a long because new FF57+ will automatically disable it. There is nothing we can do, that's how Firefox team implemented. 
We try to fix everything that is possible.

Highly recommend using EverSync to backup your dails.
https://addons.mozilla.org/en-US/firefox/addon/fvd-synchronizer

Thank you.

Thanks for the rollback link. I hope your team will be able to work out the bugs and through the Firefox limitations. As a comparison, here is what the legacy version looks like with the same URL thumbnails. Couldn't get the full screen, but there is enough to see the difference.

Ok. Also:

Highly recommend using EverSync to backup your dails. https://addons.mozilla.org/en-US/firefox/addon/fvd-synchronizer

Well, I have to say either you or Mozilla staff did something to help with the new speeddial update. I had the legacy installed, but got a forced update to the newer version. I have to say the preview resolution is improved from the first version update. The sites are still somewhat overblown in the largest thumbnail size, but it's doable. I had to remove the dial that pointed to a local html file because the window continuously clocked. Once removed, all the previews load. Here's a screen shot of the most recent speeddial update. Money dot com international markets dial replaces the local weather html file.

Unrelated, I would suggest you set the default dial refresh rate to something greater than 1 minute. I know it can be configured, but for some not so tech savvy, something like 15 minutes might be better for the Internet while still providing the ability to reduce time down to 1 minute if desired.

Ok. we will do that.

Thank you