The Admin Guide tells to run admin/check/index.php after upgrading.
There you get a warning, to check the fileinfo extension.

I disabled the php extension and I ran the check script in v2.8.1 and v2.10.0.

Both reports contain the following warning:

Fileinfo extension is available for determining file MIME types

Web clients may struggle to download files without knowing the MIME type of each attachment.

Since it's only a warning, I suppose it should not have any critical impact.

According to the logged php error, the difference is that v2.9.x & v2.10.x seems to trigger an exception whenever they call:

finfo_get_if_available()

Then I compared the versions of the utility_api.php...

v2.8.1

function finfo_get_if_available() {

if( class_exists( 'finfo' ) ) {

$t_info_file = config_get( 'fileinfo_magic_db_file' );

    if( is_blank( $t_info_file ) ) {
        $t_finfo = new finfo( FILEINFO_MIME );
    } else {
        $t_finfo = new finfo( FILEINFO_MIME, $t_info_file );
    }

    if( $t_finfo ) {
        return $t_finfo;
    }
}

return null;
}

v2.10.0

function finfo_get_if_available() {

$t_info_file = config_get_global( 'fileinfo_magic_db_file' );

if( is_blank( $t_info_file ) ) {
    $t_finfo = new finfo( FILEINFO_MIME );
} else {
    $t_finfo = new finfo( FILEINFO_MIME, $t_info_file );
}

if( $t_finfo ) {
    return $t_finfo;
}

return null;
}

... and I found that the newer one seems to have a regression.
It doesn't test the existence of 'finfo' class anymore.

The following one is a safer function version for the v2.10.x.

function finfo_get_if_available() {

<b>if( class_exists( 'finfo' ) ) {</b>
    $t_info_file = config_get_global( 'fileinfo_magic_db_file' );

    if( is_blank( $t_info_file ) ) {
        $t_finfo = new finfo( FILEINFO_MIME );
    } else {
        $t_finfo = new finfo( FILEINFO_MIME, $t_info_file );
    }

    if( $t_finfo ) {
        return $t_finfo;
    }
<b>}</b>
return null;
}

I tested it on my system (without the extension), and everything is returned to work fine as usual.

Regards