Dan claims the folks behind the explosive documentary defamed him by falsely implying he was a child sexual abuser at Nickelodeon ... and a judge just ruled Dan's case can proceed.

The former TV exec filed suit against Warner Bros. Discovery and Sony Pictures Television, among others, back in May after the documentary was released ... but Warner Bros. and Sony tried to get the suit thrown out ... arguing the film did not actually accuse Dan of sexual abuse.

However, the judge says a "reasonable viewer might conclude" the documentary "makes damning implications about his conduct" ... and Dan set forth a legally sufficient claim that could possibly lead to a favorable judgment for him down the road.

In other words, the judge says Dan has done enough so far to continue with his lawsuit.

TMZ broke the story ... Dan slammed "Quiet on Set" as a "hit job" in his original lawsuit, claiming the docuseries used manipulative editing techniques to create a false impression of Schneider and lump him into the same bucket as 2 convicted child sex offenders who worked on some of the same Nickelodeon shows. Dan said the documentary producers did it all for "clickbait, ratings, and views -- or simply put, money."

Dan does, however, concede in the lawsuit he was blind to some of his bad behavior toward colleagues, subordinates and cast members ... but he's adamant such behavior was not in any way connected to child sexual abuse.