Please make sure that account or service account that you’re using has the necessary Identity and Access Management (IAM) roles. For full control over objects, including listing, creating, viewing, and deleting objects, you must have the Storage Object Admin (roles/storage.objectAdmin) role. You can check this link on how to grant an IAM role.
If you’ve verified that you have the right IAM roles, did you perhaps deleted a large amount of objects from your Google Cloud Storage bucket within the last 7 days, and/or you have a qualifying Lifecycle rule that deleted many objects from the bucket that you are attempting to perform an object listing on? When a large number of objects are deleted from a bucket, it is normal for the process of listing the remaining objects in the bucket to slow down. If the Cloud Console exceeds a certain time limit while attempting to retrieve the object listing, it will show the error message “Sorry, the server was not able to fulfill your request.” The solution for this is to retry the listing of objects within the next few days; the issue should automatically resolve within seven days. See documentation.
Lastly, try to re-log in again as you might need to re-authenticate again to generate a valid login token so you can access GCS.
We did not delete massive amount of objects within the last 7 days. I am the owner of the account and have storage&object admin permissions, others who has the same issue has storage object admin permission. This time these two common cause of unable to access buckets/objects are not the issue triggers.
My issue is caused by my corporate policy. I verified AWS Workspace are running in 10.x.x.x/8 CIDR and company laptop connecting via VPN are in 172.x.y.z/12 CIDR. Checked with corporate cloud security, the 172.x.y.z/12 CIDR is not in organization VPC control policy to allow to access cloud storage.
Working with corporate security and cloud development to identify the scope of impact and best solution for the issue.