Check that this is really a bug
Reproduction link
https://codesandbox.io/s/wild-fire-c3dsz1?
Bug description
The newest release is completely unusable for me, since I get the ,,Unable to find node on an unmounted component" error.
Reverting to 0.39.3 solves the issue.
Expected Behavior
No response
Actual Behavior
No response
react-big-calendar version
0.39.4
React version
16.14.0
Platform/Target and Browser Versions
Microsoft Edge 99.0.1150.36
Validations
Would you like to open a PR for this bug?