I think KNIME automatically updates all of the packages if you enable the nightly build update-site. Can you update all with the nightly build and see if the error still occurs?
Doing so now. I think it downloads everything, but the next step is a menu, there I only picked the Tess4J associated stuff, instead of everything. I now update everything.
Strange things happened, now the FeatureCalculator works, however it threw out my manually copied macro from its folder, and therefore my workflow stopped working...
Edit: found the error. The nightly build put in a new ImageJ v1 folder, so it is now not found, but it is still present in the old folder.