Error when using countSearch: Cannot read property 'toJSON' of null

[Drarok]

Stack trace as follows:

[2021-12-07T19:32:03.826Z] error TypeError: Cannot read property 'toJSON' of null
    at Child.<anonymous> (/mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:126:54)
    at processImmediate (internal/timers.js:464:21)
From previous event:
    at /mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:126:18
    at step (/mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:33:23)
    at Object.next (/mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:14:53)
    at /mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:8:71
    at new Promise (<anonymous>)
    at __awaiter (/mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:4:12)
    at exports.countSearch (/mnt/dev/cms/node_modules/strapi-deepsearch-service/dist/services/deepsearch.js:117:65)
    at Object.countSearch (/mnt/dev/cms/api/page/controllers/page.js:44:21)
    at dispatch (/mnt/dev/cms/node_modules/koa-router/node_modules/koa-compose/index.js:44:32)
    at next (/mnt/dev/cms/node_modules/koa-router/node_modules/koa-compose/index.js:45:18)
    at dispatch (/mnt/dev/cms/node_modules/koa-compose/index.js:42:32)
    at /mnt/dev/cms/node_modules/strapi/lib/middlewares/router/utils/routerChecker.js:79:28
    at dispatch (/mnt/dev/cms/node_modules/koa-compose/index.js:42:32)
    at module.exports (/mnt/dev/cms/extensions/users-permissions/config/policies/permissions.js:132:9)
    at async /mnt/dev/cms/node_modules/strapi-utils/lib/policy.js:68:5
    at async serve (/mnt/dev/cms/node_modules/koa-static/index.js:59:5)
    at async /mnt/dev/cms/node_modules/strapi/lib/middlewares/parser/index.js:48:23
    at async /mnt/dev/cms/node_modules/strapi/lib/middlewares/xss/index.js:26:9
[2021-12-07T19:32:03.826Z] debug GET /pages/countSearch?_q=Decision&token=SUPER_SECRET_TOKEN&_limit=10&_start=10 (90 ms) 500