What was the central issue Lonnie Johnson alleged against Hasbro when he initiated legal action in 2013?

Answer

Being underpaid royalties for the period from 2007 to 2012

In 2013, Johnson took legal action against Hasbro, alleging that he was being underpaid royalties for the Super Soaker and several Nerf products covering the years 2007 through 2012.

What was the central issue Lonnie Johnson alleged against Hasbro when he initiated legal action in 2013?
inventortoySuper SoakerLonnie Johnson