A popular cryptocurrency exchange in Japan experienced a temporary glitch that allowed investors to purchase cryptocurrency including Bitcoin for free—though no users were able to profit off of the issue.

The issue, first reported by Reuters, plagued the Zaif exchange for about 20 minutes on Feb. 16, though the glitch wasn’t publicly revealed by the exchange operators until Feb. 20.

Cryptocurrency A Japanese cryptocurrency exchange experienced a glitch that briefly dropped the price of Bitcoin to zero. Photo: Make-someones-day/Pixabay

The issue for Zaif, a government-registered exchange run out of Osaka, came and went relatively quickly. The bug temporarily priced Bitcoin at zero yen, but the company quickly caught wind of the problem and shut it down.

During the 20 minute period that Bitcoin was free on the exchange, seven customers bought he cryptocurrency for free. Those transactions were voided by Zaif after discovering the error and operations continued as normal.

Unfortunately for Zaif, one of those customers who purchased Bitcoin while the glitch was active has been unwilling to accept the mistake and has been fighting to keep his profit from purchasing the free Bitcoins.

According to Japanese news outlet Asahi Shimbun, the customer in question purchased 2,200 trillion yen (about $20 trillion) worth of Bitcoin and attempted to cash out the free Bitcoins immediately. The sell order was for more value than the entire market cap of Bitcoin, which sits at more than $183 billion.

Zaif has not provided any details regarding the status of the situation with the customer who has insisted on being allowed to cash out the free Bitcoin, though it seems unlikely the user will be able to hang on to what would amount to the largest fortune on earth.

The issue has just been the latest in what has been a string of shortcomings for cryptocurrency exchanges in Japan, which have resulted in additional government scrutiny and questions from consumers who use the platform.

Japan has been an early adopter of cryptocurrency, going so far as to recognize the cryptocurrency as a legal payment method in 2017. The country has also been on the forefront of regulating cryptocurrency markets and began issuing licenses to exchanges operating within the country.

Earlier this year, Coincheck, a Tokyo-based cryptocurrency exchange, confirmed it suffered a security breach that resulted in as much as $533 million worth of digital tokens being stolen from the platform. The breach was the biggest single heist of cryptocurrency, surpassing the infamous Mt. Gox incident that resulted in $450 million worth of Bitcoin being stolen.

As a result of the Coincheck hack, some investors sued the cryptocurrency exchange over the incident and the decision to freeze all assets, temporarily making it impossible for investors to pull their funds out of the exchange.