What happens when you enter Verdistis? There should be a cutscene conversation triggered when you move forward with a guard that wakes up long enough to welcome you. The game could have a problem starting or ending something with that NPC.
Try starting a new game and save under a unique name, then use iZakaroN's SaveEditor
(or from Kiya's site
, with description) to give that character a large constitution and/or experience boost, reload the save, kill a rabbit or open the catacombs to level if you gave yourself experience, and run to Verdistis.
Alternately, you could hex teleport
a new character to the entrance of Verdistis (coordinates 81 71, F0 05) if you are comfortable hex editing.
If a new games works, then the problem is likely in your existing character's save files, which may still be fixable. If a new game crashes, as well, the problem would more likely be with the game itself, in which case a clean install may help.
Check your messages (click 'My Stuff' in the top menu bar, then 'Messages').Troubleshooting Tips (& manual install procedure)