Upload failure caused by CORS failure

One of my users is unable to upload files. They get the red “Can’t Upload” error in the upload widget. I’m unable to reproduce the issue on my machine, but I was able to get on a screen share to see it happen. Looking in the browser console I see:

Access to XMLHttpRequest at 'https://upload.uploadcare.com/base/?jsonerrors=1' from origin 'https://mydomain' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

We tried it in Chrome, Chrome incognito mode, and Edge. Same problem everywhere. It works for me so presumably it is something specific to their computer or network but I’m not sure how to track it down any further. Any ideas?

Hi @jack, the issue seems to be specific to the user’s environment. Perhaps, access to upload.uploadcare.com is being blocked in the user’s network. Are they using any antivirus or VPN software? Is it a home or office network? If so, they may need to reach out to their network administrator to whitelist uploadcare.com and its subdomains. If it’s not the case, please ask the user to open a support ticket with us, and we’ll help investigate the problem further.