IF you’re doing TS you can also use a ? on the *ngIf for the element and it will optionally check for an instance of Ads (true false i believe) or go by length if array. Should work for ya.
<ion-slides autoplay=“3000” *ngIf=“Ads?.length > 0” class=“slideroption” loop=“true” speed=“300”>
<ion-slide *ngFor=“let Ad of Ads”>
<img [src]=“Ad?.image”>
The error message tells you exactly what is wrong, and if you had proper types on all of your object properties, you would have been warned at compile time that you are trying to assign a string “no records” to what is supposed to be an array.
You have to remember that Ionic 3 is really just a UI framework. At it’s core an Ionic 3 app is Angular 4 code, and you can use any standard Angular syntax. So it might be good to learn Angular outside of Ionic as well, just so you have a better grasp of Angual as a whole and not just the Ionic subset.