The module gets enabled without any errors. You can also visit the revision page, however, it shows only one revision (and no graph).
Active
2.1
Code
See module page:
NOTE: The module relies on recording some Revision history. This happens only when the module is enabled. Thus the graph won't be reliable for period when the module was not in use.
So create some revisions and see if the graph appears...
@maxilein, you are right! sorry false alarm!