Dear Armand66,

Please open CuteSoft_Client\CuteEditor\Configuration\Security folder,

Edit the filenamePattern security of these security file

<security name="filenamePattern">^[a-zA-Z0-9\._\s-\#]+$</security> 

Using your own regex for this setting. 

For example, set it to ^[éa-zA-Z0-9\._\s-\#]+$

The file name in your post is allowed. 

Regards,

Jeff