I can´t upload files or create new folder

When I want to upload files or create a new folder it says its not possible or that there is an unnokn problem. I have this issue since December.
Thank you for your help

Hello there ,

welcome to the community of Nextcloud.

You started a topic in support category.
Unfortunately you ignored the template and a lot of information to help you is missing.

Please add all necessary information like Nextcloud version, webserver type and version, os version, related log file content.

Without additional information the community members cannot help you.

Regards,
rakekniven