Error building the project

[raihanameen]

Hey @mehulmpt I got this below error, I checked the return statement as well everything looked fine, but I am still not able to run it

Server Error
Error: Error serializing `.posts` returned from `getStaticProps` in "/".
Reason: `undefined` cannot be serialized as JSON. Please use `null` or omit this value all together.

This error happened while generating the page. Any console logs will be displayed in the terminal window.
Call Stack
isSerializable
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/lib/is-serializable-props.js (7:95)
<unknown>
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/lib/is-serializable-props.js (7:503)
Array.every
<anonymous>
isSerializable
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/lib/is-serializable-props.js (7:304)
isSerializableProps
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/lib/is-serializable-props.js (9:219)
renderToHTML
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/next-server/server/render.js (30:508)
processTicksAndRejections
node:internal/process/task_queues (96:5)
async
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/next-server/server/next-server.js (76:329)
async __wrapper
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/lib/coalesced-function.js (1:330)
async DevServer.renderToHTMLWithComponents
file:///Users/raihanameen/Downloads/GitHub/ghost-cms-nextjs/node_modules/next/dist/next-server/server/next-server.js (99:364)