Hello to everyone who knows how to solve the problem? (mac os)

Generally the Disk Write Error on Steam happens because the Steam client does not have proper permissions to access your storage drive. 
You can find steps to resolve this issue by following the steps here: 

• Update and Installation Issues on Steam: https://help.steampowered.com/en/faqs/view/21F5-8D5D-0141-7A5E

Should the steps in the guides above have not been able to help resolve your issue, your best next step is to contact Steam Support directly: https://help.steampowered.com/ 
You can also find help in the Steam Community Forum: https://steamcommunity.com/discussions/ 

JanH Before I updated the game, a couple of minutes ago also, I updated another game and it updated successfully, but this one didn't.

Regrettably, because the issue is happening outside of the game, we do not have any ability to assist outside of the troubleshooting steps we have provided in the link above. I've included it here once more for your reference: 

• Update and Installation Issues on Steam: https://help.steampowered.com/en/faqs/view/21F5-8D5D-0141-7A5E

That said, I looked around and was able to find some troubleshooting guides that should be of help for for users who encounter the Disk Write Error on Steam: 

• How to Fix the Steam Disk Write Error (via Lifewire): https://www.lifewire.com/how-to-fix-steam-disk-write-error-4687188
• Failed to Start Game: https://help.steampowered.com/en/faqs/view/3A2A-BF2D-15FF-7963

Additionally, it looks like people on Reddit who were experiencing a similar Disk Write Error (whilst playing different games on Mac OS) posted about their experience with the error here: https://www.reddit.com/r/macgaming/comments/yrwlfu/steam_disk_write_error/ 

And should the steps in the guides above have not been able to help resolve your issue, your best next step is to contact Steam Support directly as they would be better equipped to assist with update/download issues on Steam: https://help.steampowered.com/

 

JanH Thank you very much, I was able to solve it with the help of the reddit link, thank you again and good life to you and your family.

Changed Status to Closed