test-update vm 2.6.0 to vm 2.9.1 on joomla 2.5.20

[CE WebDesign München]

test-update vm 2.6.0 to vm 2.9.1 on joomla 2.5.20

product-editing:
can't switch language, not even to english (popup "invalid token"), but english content is there
all customfields gone
can add related products but gone after save

can save config but blank page after save&close

just for info: targz won't work for me (issue with other extentions too), had to manually unpack folders

xampp1.8.3 with php5.5.9

kind regards

[Milbo]

Then please follow the docs and use the tableupdater in the BE. Else it is clear that nothing works.