ok, I ended up with this combination: github.com/TYPO3-extensions/seminars v 0.9.99 github.com/TYPO3-extensions/oelib v 0.8.50 dl.dropboxusercontent.com/u/27225645/Extensions/T3X_ameos_formidable-1_1_563-z-201404171623.t3x v 1.1.563 (link taken from seminars documentation) so far things are looking pretty good.