We're aware that some players are having trouble logging into Fortnite on PS4 and PS5. If you're experiencing slow loading time or are unable to log into Fortnite on PS4 or PS5, try restarting your Fortnite game client.

A number of factors can cause the "PS5 was unable to launch the game or application" error. For example, it may be a PS5 system software version problem, storage device problem, system software, or game incompatibility problem. Here, I summarize some possible error reasons as follows:

• Error/bug in code

• Overheated hardware

• Unstable power supply

• Storage device failure

• Corrupted or missing system files 

• Not enough storage space on the device

Read more: https://www.docdroid.com/UquZcZA/fortnite-not-working-on-ps5-how-to-troubleshoot-pdf