Thanks for reporting the problem.��
The error means the VM is incompatible with the image. There was a change of image format in Pharo 5, so the package has likely an old VM while the image has the new format, or the new VM while the image has the old format.��
Someone will look into that problem in the incoming weeks. Most Pharo maintainers are on Mac, we noticed recently that other OS were not maintained carefully enough (We're sorry about that) and we're trying to solve that problem.
Meantime....
Can you try the latest VM from here (latest.zip):
Or if still failing, the latest VM from here (latest.zip):
Thanks & Regards
Clement