About 30 people were stuck on the ride when it was stopped at about 12.00 BST.
A spokeswoman said a piece of rubber "came away from one of the carriages." "At no time were any guests at risk," she added.
The ride reopened in March, nine months after the horror crash.
Latest updates on this story
In a statement, the theme park said all visitors were evacuated from the ride in 30 minutes.
"The ride remained closed for a short period to investigate the matter, which is part of our standard process in assessing minor incidents," it added.
"The technical team have declared the ride safe and The Smiler re-opened at 16.22."
Liam Dennett, 33, from Cheltenham, was in the queue for the ride when an announcement was made about a "technical fault".
He said: "The ride's still closed now. We can see it in the distance that it's still closed. I would say between 30 and probably 35-40 minutes that they were stuck for."
He said he would not go on the ride after seeing what happened.
"My son still wants to go on it, but I wouldn't go on it personally now," he said.
Two women needed amputations after two carriages crashed on the track in June 2015.
Merlin Attractions Operations Ltd admitted breaching the Health and Safety Act after an investigation found the crash was caused by human error.

The ministry is asking for 180.5bn yen ($2.1bn, £1.3bn), some of which an official said would be spent on missile interceptors and fighter jets.
The move comes with Japan embroiled in a territorial row with China.
It also follows North Korea's recent successful long-range rocket launch.
"We will request 180.5bn yen to be allocated to military spending from a stimulus package," a defence ministry spokesman told Agence-France Presse news agency.
He said that part of it would fund the purchase of PAC-3 surface-to-air anti-ballistic missile systems and modernise four F-15 fighter jets.
The defence ministry spokesman said the funds were needed "to prepare for the changing security environment surrounding Japan".
The finance ministry has to approve the request before it can be added to the government stimulus package expected later this month.
Q&A: China-Japan islands row
The request for funds is in addition to news on Tuesday that the new government, which won elections in December, would increase the defence budget request by more than 100bn yen.
Officials say the increase would be used for research into a new radar system and maintenance costs for military aircraft.
The mooted increase is not large - the defence budget for the year ending in March 2012 stood at 4.65 trillion yen - but it represents a change.
For 10 years, Japan's defence budget has been gradually declining. But in the last few months the country has been shaken from two sides, says the BBC's Rupert Wingfield-Hayes in Tokyo.
In December, North Korea successfully launched a long-range rocket that flew over southern Japan. Much more worrying for Tokyo is China's push to claim disputed East China Sea islands, our correspondent adds.
The dispute over the islands, called Senkaku in Japanese and Diaoyu in Chinese, has rumbled for years.
Japan controls the islands but its purchase of three of them from their private Japanese owner in September sparked a renewed row.
Since then Chinese ships have been sailing in and out of what Japan says are its territorial waters around the islands, prompting warnings from Tokyo.
New Prime Minister Shinzo Abe, who is known as a conservative, has pledged a strong stance on the territorial issue while also calling for dialogue with China.

The man was wearing headphones as he worked in his home in Westfield Street in Heckmondwike, West Yorkshire, when the attacker struck on Wednesday.
He managed to call police when he regained consciousness and nothing was taken from the house.
Police said he was hit on the back of the head and treated in hospital for a minor head injury.
Any witnesses are urged to contact police.
The Smiler rollercoaster at Alton Towers had to be closed after debris fell from a carriage - 14 months after it crashed leaving five people seriously injured.
[NEXT_CONCEPT]
Japan's defence ministry says it is seeking more funds for military spending, a day after news the government would boost the defence budget for the first time in 10 years.
[NEXT_CONCEPT]
A man knocked unconscious while he was doing DIY at his home came round to find racist graffiti on the wall.