These are not Javascript errors, they are exceptions from .NET.

Looks like they are trying to parse Duration or Delay on a PowerOn command for a particular device and it is a value which is not a floating point.

Have a look at your database and for each component, see if you have a valid PowerOn Delay specified. If so, you will likely need to zip up a backup of your database and send to Belgium.

FYI, this does not occur for me on XP so I suspect it may be something specific to a component in your database.