Hi Yuichiro, 

Welcome to Box Community and glad to assist!

Looks like you're only accessing shared files and folders from your account. And to address this error, please reach out to the file owner. 

Thanks for posting! 

I am having the exact same issue.

My problem is that I am the co-owner of all the folders where I am accessing files, and I am even losing access to files that I have created and uploaded to Box Drive.
As of recent, I am no longer able to access files from Box Drive, however I can access them via browser.

For files that I create, I can initially access them directly from Box Drive once uploaded, but after a few days I lose access.

I have tried reinstalling Box drive, however the issue still remains.
This should not be a permissions issue since I have all the required permissions.

Any assistance would be greatly appreciated.