I have posted a new release (8-Jun-2019).
The changes (taken from the update log) are:
Monochrome: fixed problem causing background histogram to be missing in the Curve tab when editing the transformation.
Omitting the extension when saving a file now sets the extension automatically to the default in all cases. Previously, it worked this way in some cases but not others.
Updated to ExifTool 11.49
Bug fix release 8-Jun-2019
Moderator: jsachs
Bug fix release 8-Jun-2019
Jonathan Sachs
Digital Light & Color
Digital Light & Color