Hi ​@Ulrich G, welcome to the Box Community!

The Free Individual plan allows file uploads of up to 250 MB. If you’re experiencing issues uploading, there may be other factors affecting the process that we need to identify in order to assist you effectively. To help us isolate the issue, please review the troubleshooting guides below:

• Are you uploading to your ‘own’ account or to someone else’s folder as a collaborator? If it's the latter, kindly check with the account owner to ensure there is sufficient available storage for new uploads.
• Make sure that your web browser is the latest version of Chrome, Firefox, Safari, or Edge. An out-of-date browser can cause file upload problems.
• Clear your browser's cache.
• Verify that you are using one of our supported operating systems.
• Check your network connection to Box. If connected to the internet with a wireless card, try a wired LAN connection. Check to see if the connection to the internet drops intermittently. If this is the case, we recommend the Folder upload method.
• Try temporarily disabling or configuring your firewall to allow Box as a trusted site. You may find that your anti-virus software includes a built-in firewall that is impacting performance. If you are attempting to access Box from an office location and experience upload issues, then please contact your IT administrator or internal Help Desk.

Please check out Troubleshooting Uploads to Box to learn more. It outlines common causes of upload issues, including potential reasons for slow uploads.

We look forward to helping you get this resolved.