I think customer support only works weekdays during UK business hours. You should probably raise a ticket if you have not already done so. You could also save your project as a .scribe file and attach it here if you would like help from other users.

Make sure your file name only contains letters and numbers. You can try restarting videoscribe and you can try saving a different video format, but it would be difficult to guess what is wrong with the project using only the information you have provided.