This is Magento bug. Wrong paths to Windows are generated. The fixed fix is

Magento 2.3.0

#/vendor/magento/framework/View/Element/Template/File/Validator.php:114

the string

$realPath = $this->fileDriver->getRealPath($path);

to replace

$realPath = str_replace(‘\’, ‘/’, $this->fileDriver->getRealPath($path));

Magento 2.2.7

/vendor/magento/framework/View/Element/Template/File/Validator.php:113

code

protected function isPathInDirectories($path, $directories)
{
    if (!is_array($directories)) {
        $directories = (array)$directories;
    }
    foreach ($directories as $directory) {
        if (0 === strpos($this->fileDriver->getRealPath($path), $directory)) {
            return true;
        }
    }
    return false;
}

to replace

protected function isPathInDirectories($path, $directories)
    {
        $realPath = str_replace('\\', '/', $this->fileDriver->getRealPath($path));
        if (!is_array($directories)) {
            $directories = (array)$directories;
        }
        foreach ($directories as $directory) {
            if (0 === strpos($realPath, $directory)) {
                return true;
            }
        }
        return false;
    }