Weka Segmentation Issue error

I was having an inexplicable error with weka recently so I redownloaded FIJI entirely. However, now when I try to run trainable weka segmentation, I will not train the classifier and gives the attached error message. please help!!

Hey @mwa,

please activate the “ImageScience” update site in Fiji and run Weka again.

Let us know if this solves the problem!