I am using Windows 10 and do not see this behavior.
I also did not manage to reproduce it.
Can you send a screenshot?
About the server error:
probably it was something temporary.
Just converted to Windows 10 64bit and noticed that when I click on the
Favorites 'gold star' instead of getting a preselected box size showing all the
items I get a very small box about 2cm square popup with just the words
'Edit Comment' visible in the top left corner of screen.
If I resize it to view all and position it as required it only sticks
until I exit the program. On reopening the problem re-occurs.
Not used Webdownloader for awhile so no sure if it is related
to change from Windows 8.1 to 10.
Strange as never had this issue before.
The previous request for a download an album in one go,
retaining album name, feature is a great idea.