Hello. I have trying to upload a pdf file to Gemini-2.5-flash from my server action. I am repeadedly getting the "The document has no pages." error. The pdf has 1 page. I can't seem to find anything related to this issue in the docs. Please help.

"use server";
import { google } from "@ai-sdk/google";
import { generateObject } from "ai";
import z from "zod";

export async function scanPdfUsingAI({
  base64String,
}: {
  base64String: string;
}) {
  // Convert the base64 string to a file buffer
  const fileBuffer = Buffer.from(base64String, "base64");
  console.log("File buffer", fileBuffer);

  const { object } = await generateObject({
    model: google("gemini-2.5-flash"),

    schema: z.object({
      response: z.string(),
      score: z.number(),
    }),

    system: prepareSystemPrompt(),

    messages: [
      {
        role: "user",
        content: [
          {
            type: "text",
            text: "Review the CV.",
          },
          {
            type: "file",
            data: fileBuffer,
            mediaType: "application/pdf",
          },
        ],
      },
    ],
  });

  return object;
}

function prepareSystemPrompt() {
    ...
}

Getting this -

 ⨯ Error [AI_APICallError]: The document has no pages.
    at async scanPdfUsingAI (app/actions/scan-pdf-using-ai.ts:15:22)
  13 |   console.log("File buffer", fileBuffer);
  14 |
> 15 |   const { object } = await generateObject({
     |                      ^
  16 |     model: google("gemini-2.5-flash"),
  17 |
  18 |     schema: z.object({ {
  cause: undefined,
  url: 'https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent',
  requestBodyValues: [Object],
  statusCode: 400,
  responseHeaders: [Object],
  responseBody: '{\n' +
    '  "error": {\n' +
    '    "code": 400,\n' +
    '    "message": "The document has no pages.",\n' +
    '    "status": "INVALID_ARGUMENT"\n' +
    '  }\n' +
    '}\n',
  isRetryable: false,
  data: [Object],
  d