MLflow 1.23.1 is a patch release containing the following bug fixes:

• [Models] Fix a directory creation failure when loading PySpark ML models (#5299, @arjundc-db)
• [Model Registry] Revert to using case-insensitive validation logic for stage names in models:/ URIs (#5312, @lichenran1234)
• [Projects] Fix a race condition during Project tar file creation (#5303, @dbczumar)

Note: Version 1.23.1 of the MLflow R package has not yet been released. It will be available on CRAN within the next week.