Walking around that issue I finded solution:
1. this problem occurs when there are multiple versions of scheduler in the project
2. for check this use
npm list scheduler, or
yarn why scheduler (more info
here and
here)
3. if you have several versions of scheduler check link above or
- use with npm
this
- use with yarn like this:
"resolutions": {
"scheduler": "0.15.0"
}
4. in any case after each manipulation with scheduler
ALWAYS reload you react app (e.g. npm start)