After a bit of refactoring our codebase this error started showing up during tests.
Can't bind to 'ngIfContext' since it isn't a known property of 'ng-container'
I found a few results from google but nothing that solved the problem. I started pulling out *ngIf from the tags in the template that was linked to the component and finally found the line causing the problem.
<ng-container *ngIf="group.subgroups; else singleGroup; context: {$implicit: group }">
*ngIf does not support the context argument. The context argument works on *ngTemplateOutlet property.