The pair, who were married from 1990 to 1994, appeared to have put 18 years of public bickering behind them when Arnold showed up at a Tv roast of his ex last year (12), but it now seems the renewed friendship was short-lived.
Their latest spat began when new dad Arnold tweeted about cleaning out his garage and getting rid of old wedding videos. Barr became upset when she thought the footage was from their wedding.
The Undercover Blues star wrote, "Cleaned out garage and dropped boxes at Goodwill. Hope someone really needs 47 remote controls, 65 phone chargers and my old wedding videos."
The Roseanne star responded, "Of me? bc (because) if they are, I would like that footage since it has my kids in it - it's not really your choice 2 (to) destroy."
The former couple went back and forth trading insults, until Arnold, who has been married three times since his divorce from Barr, revealed the videos were from other nuptials.
He continued, "I've got old wedding videos from several women. Why you think it's all about You?..."
She replied, "So then your answer is: no, they are not of me or my kids? That's all u (you) really have to say."
The pair eventually made up and even exchanged some compliments - after Barr complained about being sick, Arnold wished her well and told her he would make sure none of the videos he is giving away feature her. She ended the conversation by congratulating him on his new baby - the actor became a first-time dad in April (13) when his fourth wife, Ashley Groussman, gave birth to son Jax Copeland Arnold.