Getting warning in expo router [ Layout children ] : No route named “(tabs)” exists in nested children [“+not-found”,”_sitemap”]

I was working on an app made with react-native expo it was all working fine and it is a very large project but suddenly the expo changed its version of sdk and it stopped working instead it displayed a message on a blue screen that “either use an older version of expo go app or upgrade to the latest version of sdk ” then i updated to the latest version of expo go and then when i started my app it never started i have been trying to start it from many time it is about a month and half to me trying to start it but it is not starting instead it displays a +not-found screen as

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and display me a warning that

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my folder structure is as

app / (tabs)/_layout.jsx,_layout.jsx ,index.jsx ,+html.jsx,+not-found.jsx,

(inside the app folder there is folder named as tabs and four files (,_layout.jsx ,index.jsx ,+html.jsx,+not-found.jsx ) inside tabs folder there is a file _layout.jsx )

please can anyone tell how can i fix it is a very larger project and i cannot afford to lose it

I tried everything that i can even when it not started i maded a new project of expo go and transfered all of the contents there but still i am getting the warning and my project is not working