Supervised classifications fail

Supervised classification runs return error message with the following setting:
-Mac OS
-SNAP v 7.0 with latest updates
-Landsat image using 6 TM bands (subset 3000x3000)
-7 Vector Data training areas are defined using the polygon tool

  • In classifier dialog window, the Landsat image is added in ProductSet-Reader
  • In classifier parameters window all is let as default. 7 training areas are listed and 6 TM bands are listed.
  • Output filename is default
    Error message: written in red in classifier window:

Same error with other supervised classifiers (KNN, Minimum Distance)
I tried saving file with vectors and reopen it as suggested in the forum. It returns the same error message.
Unsupervised approaches worked fine.

Thanks for helping.

currently, classification only works with data reprojected to WGS 84:

It actually worked with reprojected data.
Thank you for the hint.