module fails to upgrade

Could you please provide screenshot of this email ?

This message looks like some of these words should be on new lines, so it looks strange, this is the reason I'm asking to provide screenshot of the email, it will help us to identify and fix this problem.

Thank you, it looks correct.

To be able to upgrade the module, you need to enable option to force upgrade even if files were modified:

Studio > Settings > System > SITE SETTINGS > Force site and module auto-update, even if some files were modified

Please note that your custom modification will be overwritten in this case.

By default only if less than 5% of files are modified - you can force automatic upgrade.

If more files are modified upgrade can fail or it will be unpredictable result.

If you still want to try to upgrade and understand all responsibility you can increase 5% threshold in inc/classes/BxDolInstallerUtils.php file:

define('BX_FORCE_AUTOUPDATE_MAX_CHANGED_FILES_PERCENT', 0.05);

For example to rise it up to 20%, change it to:

define('BX_FORCE_AUTOUPDATE_MAX_CHANGED_FILES_PERCENT', 0.20);

Upgrade script checks files hash before applying upgrade, if hash isn't matching - then file is considered to be modified. 

If files weren't modified, maybe it was problems with the previous upgrades, maybe it's wasn't completed or it was some problems during upgrade.

If you are sure that files weren't modified then I think it's safe to overwrite them, however making backup before the upgrade is highly recommended.

It's the latest version, but it maybe upgrade for modules, since they are versioned separately, you can check if there updates for modules here:

Studio > Apps Market > Updates