There will be a post on our forum shortly.
Essentially, accept "Add the file BT.dll to exclusion list" when a box appears on screen in the Avast anti virus software
Free anti virus software AVAST is the culprit which has removed a file from the U-MARQ engraving software in an overnight update.
We are working on a solution and will post this on our Forum as soon as possible.
Have commissioned my supplier to manufacture these, will be available next month !
Look out for them on the U-Marq website.
You just have to ask.........