Often this is because ConQuest's configuration files have become corrupted and deleting them solves the problem.
Go to your home directory (type %USERPROFILE% into the Windows Explorer bar) then go to the View tab and make sure "File name extensions" and "Hidden items" are ticked. Delete the csds_data folder and any .csds_defaults or .csds_defaults[number] files, then try to run ConQuest again.
A complete reinstall of the CSD software may also resolve the issue.
Need more help?Contact CCDC Support online, or by email.