WordPress 5.5 was released last week and quickly followed by 5.5.1 on September 1st. 💨
In 5.5 several global JavaScript objects were removed without being deprecated. WordPress 5.5.1 adds a backfill for these globals so they no longer cause errors.
If you are a developer, take note that the new WordPress environment types introduced in 5.5 will no longer be possible to override. This brings the number of types down to four: production, staging, development, and local.
