ng-bootstrap accordion 'Cannot read property 'templateRef' of undefined'

Question

I have an Angular 2 project that I've worked on, off and on, for months. I've moved it to a new computer, and installed Angular-CLI and run it. It works, except for the ngb components, like the Accordion. They give the above error, and the page falls apart.

This is my template:

  <ngb-accordion #acc="ngbAccordion" activeIds="ngb-panel-0" TemplateRef="">
    <ngb-panel  *ngFor="let child of families.SelectedFamily.children; let i = index;"  TemplateRef="">
      <ng-template ngbPanelTitle  TemplateRef="">
        <span *ngIf="child.Nickname == child.userName">
          {{child.Nickname}}
        </span>
        <span *ngIf="child.Nickname != child.userName">
          {{child.Nickname}} ({{child.userName}})
        </span>
        <settings-child-settings [name]="child.Nickname" [userId]="child.UserId" [isPrimaryCarer]="child.IsPrimaryCarer"
                                 [primaryCarerConfirmed]="child.PrimaryCarerConfirmed" [primaryCarerDisputed]="child.PrimaryCarerDisputed"
                                 [userSetCarer]="child.PrimaryCarerSetByMe" [birthDay]="child.BirthDay"
                                 [birthMonth]="child.BirthMonth" [birthYear]="child.BirthYear"
        ></settings-child-settings>

        <settings-child-create style="float:right;margin-right: 20px" *ngIf="i == 0">
        </settings-child-create>
      </ng-template>
    </ngb-panel>
  </ngb-accordion>

and the TemplateRef='' bits are what I added to try to fix the issue. I confess to not being familiar with what a TemplateRef is, but the fact is, this code worked and then it stopped working. I have the latest version of everything, I believe. I certainly ran an NPM update to make that the case.