Roseanne Barr's Son Claims 'Roseanne' Cast Conspired to Steal Her Life's Work

Roseanne Barr's son is firing back at Michael Fishman for saying the "Roseanne" revival was "rightfully canceled" ... blasting him and the rest of the cast for selling out the woman who launched their careers.

Here's the deal ... Michael, who played Roseanne's onscreen son D.J. Conner, said in a video posted to his Instagram on Tuesday that ABC was right to cancel the show.

Michael argues Roseanne's infamous 2018 tweet was not a joke and caused real harm.

In response, Roseanne's son, Jake Pentland, tells TMZ ... he agrees real harm was done, but insists his mother was the person who suffered.

Jake claims the cast conspired to take Roseanne's show from her after taking her social media post out of context. He says they never asked Roseanne what she meant and prevented her from publicly defending herself.

As you know ... the controversy erupted in May 2018, when Roseanne posted a tweet comparing former Obama adviser Valerie Jarrett to a combination of the Muslim Brotherhood and "Planet of the Apes."

Roseanne apologized and deleted the tweet, but ABC canceled the highly rated revival hours later. The network subsequently launched "The Conners" with much of the same cast but without Roseanne, who relinquished her financial and creative rights so the spinoff could move forward.

Although Michael said he still loves Roseanne and believes good people can make mistakes, Jake clearly isn't feeling the love, telling TMZ ... "I wish him good luck in finding work one day. Hopefully selling the woman responsible for his career out was worth it for him."