Angular: conditional class with *ngClass

What is wrong with my Angular code? I am getting the following error:

Cannot read property 'remove' of undefined at BrowserDomAdapter.removeClass


Step1
Step2
Step3



Angular version 2+ provides several ways to add classes conditionally:

Type one

[class.my_class] = "step === 'step1'"

Type two

[ngClass]="{'my_class': step === 'step1'}"

and multiple options:

[ngClass]="{'my_class': step === 'step1', 'my_class2' : step === 'step2' }"

Type three

[ngClass]="{1 : 'my_class1', 2 : 'my_class2', 3 : 'my_class4'}[step]"

Type four

[ngClass]="step == 'step1' ? 'my_class1' : 'my_class2'"

You can find these examples on the the documentation page.

Stack Overflow Q#35269179, score: 2813