Code 100 Apex Legends PS4 - error code explained and how to fix

Apex Legends Code 100 for PS4 is a somewhat common error code that players experience when playing the battle royale, halting progress and presenting the error "unable to complete EA sign in". Popping up more and more, this error can be a major pain for those who are trying to win their next match or rank up their battle pass and unlock new tiers of rewards.
The error code is one of a number of codes that Apex Legends players can suffer from but as with most error codes, the problem is likely not with you and is a wider issue being suffered by EA and Respawn. So, at least you won't be alone if you do suffer from the Code 100 Apex Legends issue on PS4.
Lets dive into Apex Legends Code 100 on PS4 and explain what is means and what you can do to try and fix it.
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