Hi Lucie, 

Welcome to Box Community and glad to assist! 

Is there an error while you're uploading these files? If so, can you attach a screenshot in this forum? 

Additionally, you can try the following troubleshooting steps. 

Hope it helps! 

Hi Rona, 

No error message appeared, but for example to upload 70 files (i.e very few regarding the 5k I have to upload) it marked "uploading" for more than two hours, and never uploaded the files. I checked the link you provided but I'm already doing this...

Do you have any other idea?

Thanks for your help

Hi Rona, 

Would it be possible for you to call me? I have issues for two months now, what is quite difficult to work in good conditions. 

Otherwise, please can you look at this issue? Box stop uploading my files several times a day, even if the files or folder is less than 200mb.

Thank you, 

Lucie 

+44 73 9104 3844