Uninstall the old version and installed the deluge-0.5.6.1.exe.

Still no difference, the silent crash is still unsolved.

Alright. I've uninstalled Alpha21 and deleted the program and settings folders.

Installed the latest Deluge 0.5.6, and still facing the same problem as described.
And yes, I did restart my PC after every uninstall and after every installs but that did not help at all.

What can I do now?

That's not the point.
There is no real need to delete the config folder and installation folders for every updates.

That does not explain the problem of the new version still appears on the older version after I've deleted the new version's config folder and installation folders?

OK, I'm scratching my head over this problem for the past few days. This is going to be a long post, so bear with me. I'm very well versed in uTorrent, BitComet, & Azureus, but an absolutely newbie on the workings of Deluge. I started by installing deluge-0.5.5.95-svn2013-b21-alpha21.exe on my W...