internal error: model cannot be null or undefined and must of type "object"

[TheOnlyWei]

Hi, we are getting an error running the oav validate-spec and validate-example. This is the error

error: 
{
  message: 'internal error: model cannot be null or undefined and must of type "object". Value:false, reference:/definitions/generated.nested.ca7ca542-02f7-457a-8797-65ca2ae9341e.',
  code: 'INTERNAL_ERROR',
  id: 'OAV100',
  innerErrors: [
    Error: model cannot be null or undefined and must of type "object". Value:false, reference:/definitions/generated.nested.ca7ca542-02f7-457a-8797-65ca2ae9341e.
        at SpecResolver.resolveAllOfInModel (/home/vsts/work/1/a/unified-pipeline-runtime/common/temp/node_modules/.pnpm/[email protected]/node_modules/oav/dist/lib/validators/specResolver.js:358:19)
        at SpecResolver.resolveAllOfInDefinitions (/home/vsts/work/1/a/unified-pipeline-runtime/common/temp/node_modules/.pnpm/[email protected]/node_modules/oav/dist/lib/validators/specResolver.js:348:18)
        at SpecResolver.resolve (/home/vsts/work/1/a/unified-pipeline-runtime/common/temp/node_modules/.pnpm/[email protected]/node_modules/oav/dist/lib/validators/specResolver.js:116:22)
        at async ModelValidator.initialize (/home/vsts/work/1/a/unified-pipeline-runtime/common/temp/node_modules/.pnpm/[email protected]/node_modules/oav/dist/lib/validators/specValidator.js:105:32)
        at async Object.runScript (/home/vsts/work/1/a/unified-pipeline-runtime/public/rest-api-specs-scripts/dist/modelValidationPipeline.js:45:13) {
      level: 'error',
      [Symbol(level)]: 'error',
      [Symbol(message)]: '{"level":"error"}'
    }
  ]
}

This is the pipeline with the error: https://dev.azure.com/azure-sdk/internal/_build/results?buildId=814543&view=logs&j=14c5c170-9612-5b44-a650-13d3ca524cf8&t=4cbe29ed-7ee5-5ae8-5fbd-e8766d681690

This is the PR that ran the pipeline: https://github.com/Azure/azure-rest-api-specs/pull/13283/checks?check_run_id=2233369683