alexondoa/Angular/src/app/pages/app.error.component.html

<div class="pages-body error-page flex flex-column">
    <div class="topbar p-3 flex justify-content-between flex-row align-items-center">
        <div class="topbar-left ml-3 flex" routerLink="/">
            <div class="logo">
                <img src="assets/layout/images/logo2x.png" alt=""/>
            </div>
        </div>
        <div class="topbar-right mr-3 flex">
            <button pButton pRipple type="button" label="DASHBOARD" [routerLink]="['/']"
                    class="p-button-text p-button-plain topbar-button"></button>
        </div>
    </div>

    <div class="align-self-center mt-auto mb-auto">
        <div class="pages-panel card flex flex-column">
            <div class="pages-header px-3 py-1">
                <h2>ERROR</h2>
            </div>
            <div class="card mt-3 px-6">
                <img src="assets/layout/images/pages/error.png" alt=""/>
            </div>
            <div class="pages-detail pb-6">Requested resource is not available.</div>
            <button pButton pRipple type="button" label="GO BACK TO DASHBOARD" [routerLink]="['/']" class="p-button-text"></button>
        </div>
    </div>
</div>