what problems did he face in his acting profession?
Many problems caused because he was arrested numerous times on charges related to drugs including cocaine, heroin, and marijuana
Robert Downey Jr.
From 1996 through 2001, Downey was arrested numerous times on charges related to drugs including cocaine, heroin, and marijuana and went through drug treatment programs unsuccessfully, explaining in 1999 to a judge: "It's like I have a shotgun in my mouth, and I've got my finger on the trigger, and I like the taste of the gun metal." He explained his relapses by claiming to have been addicted to drugs since the age of eight, due to the fact that his father, also an addict previously, had been giving them to him.

In April 1996, Downey was arrested for possession of heroin, cocaine, and an unloaded .357 Magnum handgun while he was speeding down Sunset Boulevard. A month later, while on parole, he trespassed into a neighbor's home while under the influence of a controlled substance, and fell asleep in one of the beds. He received three years of probation and was ordered to undergo compulsory drug testing. In 1997, he missed one of the court-ordered drug tests, and had to spend six months
when did the first iron man movie come out 2008 what was it's genre? Superhero where was it filmed? Afghanistan,  Edwards Air Force Base ,  Point Dume in Malibu, Caesars Palace in Las Vegas, Nevada and other places too can you explain who is this superhero? Tony Stark builds a mechanized suit of armor and becomes the superhero Iron Man who played this character? Robert Downey Jr.
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Robert Downey Jr. [SEP] 1996–2001: Career troubles
From 1996 through 2001, Downey was arrested numerous times on charges related to drugs including cocaine, heroin, and marijuana and went through drug treatment programs unsuccessfully, explaining in 1999 to a judge: "It's like I have a shotgun in my mouth, and I've got my finger on the trigger, and I like the taste of the gun metal." He explained his relapses by claiming to have been addicted to drugs since the age of eight, due to the fact that his father, also an addict previously, had been giving them to him. In April 1996, Downey was arrested for possession of heroin, cocaine, and an unloaded .357 Magnum handgun while he was speeding down Sunset Boulevard.