ConnectApiHelperTest: "Context user does not have permission to create rich text in feed"

[cropredyHelix]

I installed the software from UnofficialSF.com and when running unit tests, got this error

Class.ConnectApi.ChatterFeeds.postFeedElement: line 1458, column 1
Class.ConnectApiHelperTest.testCreateInputFromBody: line 257, column 1
10:18:52.130 (194554713)|FATAL_ERROR|ConnectApi.ConnectApiException: Context user does not have permission to create rich text in feed

The ContextUser is UserInfo.getUserId() - which is me, user with System Admin profile. The test appears to be posting a bolded element.

test class is V47

Network.getNetworkId() returns null for the test context

What permission to I need to setup for the running user to be able to execute this unit test?

[cropredyHelix]

You can resolve this - the answer is here in stackexchange. You might want to put a comment in the test method to indicate what to do if this error occurs.