Final Fantasy XIV has encountered an error, the program will shut down.

I recently upadated to the new patch 5.1, and I unlocked the dungeon The Grand Cosmos. But when I want to launch it, the team forms and then my game crashes, with the following message "Final Fantasy XIV has encountered an error, the program will shut down(.17)".
I tried several times, and it always crashes. Then it crashed a few times on the loading screen when I log in, before I rebooted my PC, which made the game able to load. However the dungeon still crashes.

I have Windows 10, DX11 enabled and working fine. Last year my game crashed in a similar way, I resolved the problem by reinstalling it completely, but now I want to know if there are other solutions because I have a slow internet since a few months.

Good morning and thank you for posting in the Final Fantasy XIV Technical Support Forums.

Do you experience the crash anywhere else in the game? Were any updates or changes made to the PC that coincide with the crash? Could you also provide a system report? Simply go to the 'Config' option on the Final Fantasy XIV launcher and to the right of 'System Information' click on 'Display.'

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