If the Groove Browser in your MixWave Kontakt drum library is empty even though the MIDI groove files are present in the library folder, check the format of the drive where the library is installed. The library may otherwise load and play normally.
Check the drive format
On macOS, open Applications → Utilities → Disk Utility.
Select the volume containing your library.
Check its format description.
Case-sensitive drive formats, such as APFS (Case-sensitive), can prevent grooves from appearing. Standard APFS is non-case-sensitive.
Install the library on a compatible drive
Install or relocate the complete drum library to a drive using a non-case-sensitive format, such as standard APFS on macOS. For an existing installation, follow Moving a Library to Another Location in the related articles below.
After installing or relocating the library, reopen it in Kontakt and check the Groove Browser. Reinstalling on the same case-sensitive volume will not resolve the drive-format incompatibility.
For more information about drive compatibility, see Native Instruments: Notes on Hard Drive Formats on Mac Computers.