Not sure if it is related to this plugin : cannot activate it, critical error

Hello from France! (again…. ^^)

I am the guy who post this request:

I am trying to activate this plugin (Redis Object Cache) on another website but there is a fatal error preventing it to work.

[27-Jun-2023 21:47:30 UTC] PHP Fatal error: Cannot declare class MultiSafepayAPI\Client, because the name is already in use in /vhosts/www.gladiatorfit.ch/html/wp-content/plugins/gift-voucher-pro/vendor/multisafepaygift/models/API/Client.php on line 5

I am quite sure this is not related to Redis plugin because it works perfectly on others websites.

The plugin generating the fatal error is:

Anyway, would you have a hint?

If you feel this “question” is out of range or useless, feel free to delete it!

I do not want you to spend your time on an “external” problem.

Have a great evening! 🙂