Tens of thousands of users have reported a Google outage.

According to outage monitor Downdetector, tens of thousands of users reported being unable to access several Google services on Monday night.

“User reports indicate that Google Maps has been experiencing issues since 9:36 PM EDT (0136 GMT),” Downdetector tweeted.

More than 40,000 users, including those in New York City and Denver, Colorado, experienced problems using Google’s services, particularly the maps and search engine.

According to Downdetector, reports of the outage began to fade after around two hours, but a tiny number of users continued to claim difficulty accessing Google’s cloud and calendar capabilities.

“We’re aware of a software upgrade issue that happened late this afternoon Pacific Time and briefly hampered the availability of Google Search and Maps,” a Google spokeswoman stated.

“We worked fast to resolve the issue, and our services are now operational again.”

Some users on Twitter shared screenshots of the 500 error notice they saw while attempting to use Google, which stated that the server had “encountered a problem and could not finish your request.”