Upgraded to Version 0.14.16 still getting Sanity check failed for source (passed

Hi:

When this plugin works, it’s great, ran into the latest issue where I see:

Sanity check failed for source (passed as absolute path on nginx): Path is outside allowed path

Few things about my setup:

I do not have a standard wp-content directory and am using:

location ~* ^/app/.*\.(png|jpe?g)$ {
    add_header Vary Accept;
    expires 365d;

    if ($http_accept ~* "webp"){
        set $whattodo A;
    }
    if (-f $request_filename.webp) {
        set $whattodo  "${whattodo}B";
    }
    if ($whattodo = AB) {
        rewrite ^(.*) $1.webp last;
    }
    if ($whattodo = A) {
        rewrite ^/app/.*\.(jpe?g|png)$ /app/plugins/webp-express/wod/webp-on-demand.php?xsource=x$request_filename&wp-content=app last;
    }
}

location ~* ^/app/.*\.webp$ {
    expires 365d;
    if ($whattodo = AB) {
        add_header Vary Accept;
    }
}

I see images without a problem when I am logged in. I get “Sanity check failed for source (passed as absolute path on nginx): Path is outside allowed path” when not logged in.