The PlayStation Store Twitter feed said Friday that some users were having trouble logging into its network. It said engineers were investigating.
A notice on Microsoft's Xbox website said it knew some users were having trouble signing in. it said, "We're aware of this issue, and we're working to find a fix ASAP!"
The problems were affecting Xbox Live Core Services, though most other applications were up and running, it said.
Earlier this month the PlayStation store also experienced spells of inaccessibility. That followed a cyber attack on computer systems of Sony Pictures Entertainment that led to the release of confidential information on the Internet.
Neither Microsoft nor Sony are blaming the problem on hackers, but the hacking group "Lizard Squad" is taking credit for the outages. The group previously claimed responsibility for cyber-attacks that briefly knocked the Vatican's website, Battle.net and League of Legends offline. It also claimed credit for a bomb scare that diverted a plane carrying Sony Online's president back in August.
You can check the status of the networks with the links below:
The Associated Press contributed to this report.