SiteOrigin Widgets Bundle 1.8.5 breaks PageBuilder Backend

Hi,

I’ve been using PageBuilder along with the SiteOrigin Widgets Bundle (and various other plugins) for my site. Everything has worked perfectly until a few hours ago. When editing a page, the PageBuilder Tab no longer appears als all rows and widgets were gone. The page just displays:

The front-end of the site works as normal, however. No widgets are missing or not functioning.

Tried:
Deleting and re-installing PageBuilder -> No effect
Disabling all Page-Builder plugins except PageBuilder itself -> problem gone..
Re-enabling plugins one-by-one reveals the culprit is SiteOrigin Widgets Bundle

Running WP latest version (4.7.4), Vantage theme latest version.
SiteOrigin Widgets Bundle version: 1.8.5

I’ve tried re-installing SiteOrigin Widgets Bundle, but to no avail. Would have tried downgrading but can not find earlier releases.

Please help ASAP! Thank you!
DenW