Model don't stick to the buildplate

[SPfenning]

You might clean the flexplate with acetone and let it dry, prior to a printjob. If still nothing sticks, try to sand it slightly with some grot 400 sandingpaper. Some flexplates are simply not ready at first time and require some additional work. Have experienced it myself too, which made me to give this advise.
If still nothing sticks to flexplate, it's time to fiddle with exposure-time settings ("burn-in"-layers).