Cannot read property 'hasAttached' of undefined

[yilmazhasan]

Hi, I set up module in an ionic app, it was running well until I have updated angular cdk and material version to 9.

Now Screeng getting dim and element being focused but there is no message appearing and I'm getting this error:

_Cannot read property 'hasAttached' of undefined at WalkthroughContainerComponent.push../node_modules/angular-walkthrough/ivy_ngcc/fesm5/angular-walkthrough.js.WalkthroughContainerComponent.attachTemplatePortal (angular-walkthrough.js:1784) at WalkthroughComponent.push../node_modules/angular-walkthrough/ivy_ngcc/fesm5/angular-walkthrough.js.WalkthroughComponent._attachWalkthroughContent (angular-walkthrough.js:1110) at WalkthroughComponent.push../node_modules/angular-walkthrough/ivy_ngcc/fesm5/angular-walkthrough.js.WalkthroughComponent._attachContentTemplate (angular-walkthrough.js:1374) at WalkthroughComponent.push../node_modules/angular-walkthrough/ivy_ngcc/fesm5/angular-walkthrough.js.WalkthroughComponent.setFocusContinue (angular-walkthrough.js:1269) at WalkthroughContainerComponent.push../node_modules/angular-walkthrough/ivy_ngcc/fesm5/angular-walkthrough.js.WalkthroughContainerComponent.hightlightZone (angular-walkthrough.js:1870) at angular-walkthrough.js:1248 at ZoneDelegate.push../node_modules/zone.js/dist/zone.js.ZoneDelegate.invokeTask (zone.js:421)