White blobs on 'AddOns' page and 'Troubleshooting' page

[LinuxOnTheDesktop]

Very nice AddOn. However, there are some problems. Here is one:

Here is another:

Thunderbird 68.6.0 x64
Windows 10 Pro x64 1909
ShadowBird: latest ('Latest commit 6cc2a3d on 14 Oct 2018')