Obed, whilst I understand your frustration, I have used every version of WX5 from V8 through to V13 and never experienced this issue. With rare exceptions leading to the most recent release of V13, this type of issue has primarily been due to hardware or Windows component issues.  What version of Windows are you using and was it perhaps updating at the time. Had you done any previews of your project in 5-6 hours, because if so it should have saved each time.  Have you considered, or do you have access to an iwzip of the project, and after reboot/restart WX5 can you open the project?  If so, have you verified only a loss of most recent amendments?