Horizon rejecting to modify quotas for tenants with error message

[mhg]

Brief Description
-----------------
On a lab, attempt to modify quotas using Horizon dashboard (logged as admin) for tenants, triggered error message pop-up "Danger, An error occurred. Please try again later."
While CLI "openstack quota set --<qutoa=nnn> tenant1" worked.

Here're some error messages:
cinder/cinder-volume.log:2018-09-11 17:54:00.721 178621 ERROR cinder.volume.manager [req-856371ae-a66f-4b82-9a16-c4cb5a745856 - - - - -] Failed to initialize driver.: AttributeError: 'NoneType' object has no attribute 'lower'
cinder/cinder-volume.log:2018-09-11 17:54:00.721 178621 ERROR cinder.volume.manager Traceback (most recent call last):
cinder/cinder-volume.log:2018-09-11 17:54:00.721 178621 ERROR cinder.volume.manager File "/usr/lib/python2.7/site-packages/cinder/volume/manager.py", line 442, in init_host
...

Severity
--------
Major

Steps to Reproduce
------------------
1) log into Horizon dashboard as admin
2) select Identity -> Projects
3) select 'Modify Quotas' from the drop-list for 'tenant1'

Expected Behavior
------------------
A windows should pop up allowing various quotas to be modified.

Actual Behavior
----------------
A error message window popped up, showing message "Danger: An error occurred. Please try again later."

Reproducibility
---------------
Reproducible

System Configuration
--------------------
any configuration

Branch/Pull Time/Commit
-----------------------
master as of "2018-09-10_20-18-00"

Timestamp/Logs
--------------
20180911 17:46:00

[Frank Miller (sensfan22)]

Tagged as stx.2018.10 since Horizon panel plug-ins in stx-gui is a 2018.10 deliverable.

[Kristine Bujold (kbujold)]

This bug now appears to be fixed in a build dated 2018-09-21 and build commit cgcs-root/stx/stx-gui 29637dcf6ecdfba58a7255697a75096d932bc9bc

[mhg (marvinhg)]

Retested on load "2018-09-24_20-18-00", the problem could no be reproduced.
After clicking 'Modifiy Quotas' drop-down menu-item, 'Edit Project' Window pops up for user to change quotas.
No issues found.