Google diagnosed a widespread outage that knocked out major services last week, such as Gmail and YouTube, as a mistake with its system for identifying people online.

Alphabet Inc’s Google has several tools that enable it to verify and track logged-in users. In October, the company began moving those tools to a new file storage system, and in the process misreported portions of the data, according to a Dec 18 post. That caused several of its services to go down for 47 minutes on Dec 14, a rare technical misstep.

Google’s explanation comes amid heightened cybersecurity vigilance. A hack on software provider SolarWinds Corp has exposed companies including Microsoft Corp and multiple US government agencies. A Google spokeswoman said on Friday that the Internet giant has found no evidence the SolarWinds hack affected Alphabet or Google’s systems.

About 15% of requests sent to Google’s cloud storage service were disrupted during the Dec 14 outage, the company said. The cloud division offers an identification service similar to one from Okta Inc.

On Dec 15, Google’s Gmail service had another disruption. The company attributed this to an issue with data migration.

 - Bloomberg