My JDownloader crashed and my queue is empty.
Based on what I found from Googling, I unzipped database.zip into the config directory, but it didn't help.
How can I get my queue back?
If you are using jdownloader2 beta, chdir into the cfg directory, where you should find a number of downloadListXXX.zip files where XXXX is some number. Shutdown jdownloader2, rename or copy the latest file into downloadList.zip (save your existing downloadList.zip somwhere if it exists), and finally start jdownloader2 and most of your download links should be restored.
I recomended look at the dates and sizes, use the second one that has the most recent date, the most recent shoud be had a size 1K (the empty list generated to switch off JDW), the second should be have a taller size.
Move all of later date to another site, JDW2 look to take the most recent date.