Unable to upload files

Hi Rob, 

Welcome to Box Community and glad to assist! 

If you are having trouble uploading files or folders, please try the following troubleshooting steps:

• Please ensure your web browser is the latest version of Chrome, Firefox, Safari, or Edge
• Try clearing your browser's cache. If this does not resolve your issue, please proceed to the next step.
• Verify that you are using one of our recommended operating systems.
• Verify that the file's name is valid. Box only supports file or folder names that are 255 characters or less. File names containing non-printable ascii, "/" or "\", names with leading or trailing spaces, and the special names “.” and “..” are also unsupported. Box supports only Unicode Basic Multilingual Plane (BMP) characters in file and folder names.

  • The following reserved characters are not allowed:

    • < (less than)
    • > (greater than)
    • : (colon)
    • " (double quote)
    • / (forward slash)
    • \ (backslash)
    • | (vertical bar or pipe)
    • ? (question mark)
    • * (asterisk)
• Verify that the file or folder's path on Windows machines is under the 255-character Windows limitation. Folder paths that exceed 255 characters may truncate the content's name before uploading to Box.
• Make sure you are uploading files smaller than the maximum for your account type. To determine your maximum, click on your initials in the top-right corner of the page and select Account Settings. Then, click on Account and your Max file size will be listed under Account Details.
• Try uploading using the File upload method instead of Folder upload, or vice versa.
• Check your network connection to Box. If connected to the internet with a wireless card, 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. If you are attempting to access Box from an office setting and experience upload issues, then please contact your IT administrator or internal Help Desk.
• Proxy servers may sometimes cause failed uploads. If you see the error message: An error occurred with the upload. Please refresh the page and try again. Please contact your IT department or Help Desk and ask them to check your proxy configuration.

To find out more, please head over to this article. 

Hope it helps!