Description of problem:
While the deployment is running you see many errors (toast messages) on the page:

In Chrome:
Stack Resources could not be loaded
Cannot read property 'message' of undefined

In Firefox:
Stack Resources could not be loaded
n.error is undefined

In the console you see some more messages:
Deployment parameters could not be loaded t MistralApiError
    at c (https://****.redhat.com/tripleo_ui.js:1:774349)
    at https://****.redhat.com/tripleo_ui.js:1:774200
value @ ConsoleAdapter.js:33

ConsoleAdapter.js:33 Stacks could not be loaded TypeError: Cannot read property 'message' of undefined
    at new t (index.js:82)
    at c (HeatApiService.js:102) TypeError: Cannot read property 'message' of undefined
    at new t (https://****.redhat.com/tripleo_ui.js:1:809813)
    at c (https://****.redhat.com/tripleo_ui.js:1:2162942)
value @ ConsoleAdapter.js:33


Version-Release number of selected component (if applicable):
openstack-tripleo-ui-9.3.1-0.20180921180343.df30b55.el7ost.noarch


How reproducible:
unknown


Steps to Reproduce:
1. I configured a plan with 3 controllers and 4 computes, no network isolation and no other settings
2. The plan was patched with the file containers-prepare-parameter.yaml, and the environment file containers-default-parameters.yaml was taken out of the plan
3. I configured an NtpServer in the properties dialog
4. Start deployment


Actual results:
As the deployment was progressing, I got a lot of errors on the screen. When the deployment completed (it was successful btw) the errors stopped showing up.

Screenshots to be attached.