File image: WhatsApp icon. AP (IOL).

INTERNATIONAL - Whatsapp users have been hit by an annoying bug that stops them from seeing the names of senders in their message notifications.

The bug, which appears to only impact iPhones, causes users to get a notification that says 'Whatsapp' instead of the sender's name.

The problem appears to have been caused by a recent Whatsapp update and it's unknown how many users are affected.  

Frustrated users worldwide have taken to Twitter to vent their anger - but there seems to be a very simple fix. 

'Hey @WhatsApp — any idea why this is happening? Not seeing sender name on all new message notifications?', user Angus Brash from London, wrote on his Twitter.

Another Twitter user, Dan Greenie, wrote: 'My Whatsapp notifications have gone from showing previews to showing sender to just saying 'message' and I have no idea why'.

'Iphone updated to @WhatsApp version 2.18.60 and now getting these notifications, without the contact name appearing!!! Help!', another Twitter user Andrew Bucknell said. 

'This bug is happening to me too', another Salvador-based user Eduardo Tourinho wrote below his post.  

However, the glitch doesn't take long to fix.

To fix the bug, go to Whatsapp Settings inside the app and click on Notifications. 

Turn it to 'Show Preview', and then go into your iPhone's settings menu.

In the Notifications menu, select Whatsapp, click 'Show Previews' and switch it to 'Never'.

This should fix the glitch, but will also remove any preview text in your Whatsapp notifications.

How to fix the bug:

WhatsApp users are reporting an issue with the messaging service that means they can't see who sent them a message when it appears in their notifications.

Users have complained of notifications just reading 'WhatsApp' meaning they can't see who sent the message without opening it. 

To fix the bug: 

1. Go to WhatsApp > Settings > Notifications > turn on Show Preview.

2. Go to iPhone Settings > Notifications > WhatsApp > Show Previews > Never

The bug only appears to impact iPhone users. 

Other users got rid of the bug by updating to the latest version of WhatsApp.  

Twitter user Fouad Raheb, who is based in Jounieh, Lebanon, wrote; 'It’s safe to update to latest WhatsApp 2.18.61.'

'They didn’t change anything but seems like they fixed notification message preview bug', he wrote.

However, lots of users who have not updated are still frustrated by the glitch.

'Does anyone know how I change my whats app settings so it come up the name of person texting me but not a preview? It’s just showing this nonsense', tweeted another user Shelby Brown, who is based in Balgrochan, Scotland. 

'What is wrong with whatsapp? Why can't I see who messaged in notification?' tweeted Karachi-based user Monaiza Azam. 

'Does anyone’s whatsapp do this after the update? i know i turned the preview off and it would usually just show the name but now..' tweeted user Luis Buttons. 

MailOnline has contacted Whatsapp for comment.

This is the second bug in a matter of days found on Whatsapp.  

Another bug found last week meant that users received messages from people the had already blocked.

Disgruntled users took to Twitter to try and find a resolution to the problem, with some complaining that it has allowed 'stalkers' to get in touch with them.

Not only could blocked users message people, they could also view their profile photo, status and other information even after they've been blocked.

Twitter user WABetaInfo, which has been a reliable source of information in the past, said users should remove the blocked contact from their address book and mute the blocked contact's chat.

Users could also go to 'Privacy Settings' in the app and change them so that only their contacts could see their status by selecting 'My Contacts'.