How to resolve error "can't read properties native element"

Question

I have developed disable and enable functionality in angular. When I click on enable I get the data and it's working fine but when I click on disable I am getting the error

"cannot read properties native element".

html file -

<div *ngIf="disabled" [attr.disabled]="disabled"> 
                <div  class="masking" [ngClass]="{'disable': mask1}" id='mask1' (window:resize)="onResizePM($event)" #Mask1
                    style="position: absolute;" [style.top.px]='Privacy_y'
                    (mousedown)="handlePrivacyMousedown($event)" (mousedown)='onWindowPress($event)'
                    (mousemove)='handlePrivacyMousemove($event)' (mousemove)='onWindowDrag($event)'
                    [style.left.px]='Privacy_x' [style.width.px]='width' [style.height.px]='height'
                    [style.display]="displayMask1">
                    <div (mousedown)='onCornerClick($event, topLeftResize)' id='mask1-top-left-resize'
                        class='mask1-corner-resize masking-resize'></div>
                    
                    
                </div>

ts file ----

privacyMaskForm: FormGroup = this.formBuilder.group({
    enable: [{ value: 0, disabled: false }],
})

channelTitleForm: FormGroup = this.formBuilder.group({
    en: [{ value: 1, disabled: false }],
    string_1: [{ value: '56Secure Cam', disabled: false }, [Validators.required, Validators.maxLength(12), Validators.pattern(AppConstant.Regex.overlay_name), Validators.minLength(3),]],
    align: [{ value: 0, disabled: false }],
})

timeTitleForm: FormGroup = this.formBuilder.group({
    e: [{ value: 1, disabled: false }],
    week: [{ value: false, disabled: false },],
});

customoverlayForm: FormGroup = this.formBuilder.group({
    en: [{ value: 0, disabled: false }],
    string_1: [{ value: '', disabled: false }, [Validators.required, Validators.maxLength(25), Validators.pattern(AppConstant.Regex.overlay_name), Validators.minLength(3)]],
});


en_privacy() {
        
    //this.toggle = true;
    //this.disabled = true;
    let inputValue = this.privacyMaskForm.value;
    if(inputValue.enable == 1){
        this.disabled = true;
    }
    else{
        //this.privacyMaskForm.get('maskControl')?.disable();
        this.disabled = false;
    }
    console.log(inputValue);
    if (inputValue.enable == 1) {
        this.main = false;