In Pro 2.6 you need at least 2 map frames on the layout. If you only have one, then a bit of hovering should show some context sensitive help. If you are really using version 1.2, you would be advised to upgrade because a lot has changed
Thank you for the feedback. I do have two map frames. The grid button is not only unavailable but invisible.
Hi @Anonymous User are You seriously writing 1.2.0 version of Pro or is that mis-spelling? You do need to upgrade if 1.2.0 is true..
For the missing "Grid" it is hard to tell from your screenshot. In the layout you need to activate a Map Frame in the Contents Pane for the Grid command to be active. ie
Not active
Active
That leaves looking for bugs on the Tech Support site
If this is the one, it is by design.
If it isn't that bug, then you will need to file a case with Tech Support