TOKYO -- When Japan rolled out its contact-tracing app last summer to fight the coronavirus, nobody expected that a major flaw affecting about one-third of users would go overlooked for more than four months.
Software failed to notify at-risk Android users for 4 months without a fix

A flaw in Japan's government-backed COVID-19 contact-tracing app was overlooked for months. (Photo by Yo Inoue)
TOKYO -- When Japan rolled out its contact-tracing app last summer to fight the coronavirus, nobody expected that a major flaw affecting about one-third of users would go overlooked for more than four months.