I updated CC to version 4.4, and now the thumbnails for Packs are no longer showing. Instead, there are generic thumbnails.

See the attached screenshot: CC44_Pack_thumbnails_not_showing.jpg.

Steps to reproduce:

1. Update to version 4.4.
2. Open Content Manager/Template and select the Pack tab.
3. Observe that only generic thumbnails are showing.

I have reset the content database, but that made no difference. I also updated CC to 4.4. on another system and had the same issue: no proper thumbnails.