It seems that widgets will not load if /appdata/system/startup.lua does not exist.
I believe this is a new issue that appears in version 0.2.0. I cannot confirm this, but...
The relevant code is from line 203 of /system/startup.lua.

Additionally, it seems that simply creating startup.lua in /appdata/system, even without any content, resolves the issue.

This issue was fixed in version 0.2.0b.