Here's the deal ... Chyna is accusing NBCUniversal and the Kardashian/Jenner family of racism on the heels of Gabrielle Union filing a discrimination complaint against the Peacock. BC's new attorney claims racism is the real reason "Rob & Chyna" never got a second season on E!, which NBCUniversal owns.

As you know ... Chyna is locked in a legal war with the entire Kardashian fam, filing a lawsuit way back in October 2017 claiming they went behind her back to NBCU and got her reality show with Rob canceled. Now she says racism is part of it too.

Kardashian-Jenner family attorney Marty Singer tells TMZ ... "This is a 2 year old lawsuit in which Chyna has changed her defense more times than we can count. Sadly, unsurprising to anyone, she has stooped to a new low, changing her defense to try to leverage the emotions and pain of the moment, insulting the pain and suffering of real victims of racial injustice and systemic racism."

Translation ... they smell Chyna's desperation in playing the racism card.

Singer adds ... "We take these allegations very seriously and once again, there is no Rob & Chyna show if there is no Rob & Chyna."

Our sources also tell us ... it was impossible to continue with a show about the couple, because BC had a restraining order against Rob and their relationship was over.

And what's more ... in previously filed docs, Rob's sisters came to his defense, offering witness statements to Chyna's alleged abuse ... and showing just how volatile the relationship was. According to the old docs, there were also witnesses who allegedly saw Chyna brandish a gun and drink heavily.

Chyna's attorney, Lynne Ciani, claims Kris secretly accused BC of beating Rob in December 2016 and went to NBCUniversal with her accusation. Ciani claims no one at the network ever informed Chyna of the allegations and says the situation would've been handled differently if BC was white.