Try following these instructions:
https://forums.steinberg.net/t/grooveagent-5-instrument-option-does-not-display-drum-parts/798517/2?u=romantique_tp
Please make sure that the content is being installed to a valid drive by opening the Steinberg Library Manager and clicking the gear icon to the top right. This shows the folder where libraries will be placed to by default.
If the Steinberg Library Manager doesn’t display any content in the Groove Agent tab, please install the content manually from the Steinberg Download Assistant by clicking the entry for your Cubase version, and then clicking Open/Install to the right of “Groove Agent SE 5 - Content”.
