If you're experiencing problems accessing Twitter notifications in its official mobile apps and in TweetDeck, you aren't alone.

After a brief Twitter outage on Tuesday, many users are experiencing a different kind of issue: missing or slow notifications.

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Notifications are either not showing up for users at all or showing up at delayed intervals. Some users are getting push notifications on their phones indicating new notifications, but visiting that pane in the app itself doesn't reveal the updates.

A quick Twitter search for "Twitter notifications" brings up plenty of user complaints.

The problem appears limited to Twitter's official mobile clients for iOS and Android, as well as the TweetDeck desktop and web applications. For whatever reason, Twitter for Mac appears to be working just fine.

Mashable first noticed issues with delayed (or nonexistent) notifications late Tuesday evening. Twitter for iPhone, Twitter for Android and TweetDeck all experienced delayed notifications.

On Twitter for Android, we received this message frequently when attempting to refresh mentions or notifications:

Twitter for Android often displays this message when attempting to load notifications. Image: Screenshot Twitter for Android

Users are seeing similar error messages in iOS. Some users are also getting signed out of their mobile applications when attempting to send messages.

Earlier today on TweetDeck, the following screen was not uncommon for several editors in our newsroom.

Tweetdeck is experiencing delays when it comes to displaying Twitter notifications. Image: Screenshot Tweetdeck

Although Twitter's media team has not responded for our requests for comment or clarification of the issue, a Twitter API developer did tell Mashable that there are some back-end problems affecting reliability, which are being worked on as a priority. It's possible those issues are impacting the Twitter apps.

Still, it does appear to be widespread and affecting users across the globe.

We'll update this post if we hear more information from Twitter or if the issue escalates or is resolved. If you're having issues with Twitter notifications, let us know in the comments and share which application you're using.