I am in the middle of programming up an IP Office and I came across an issue with the phones. I plugged a phone in and I received the following message:
Upgrade: File Access Error
I did some digging and found the solution. I decided to share it here.
This issue comes from the fact that the phone is not able to get the firmware from the system or wherever it is configured to go for the update. In my case I had configured the IP Office to retrieve its firmware from Manager, however I had the wrong IP Address in Manager. Basically what happened is the phone went looking for the firmware and couldn't retrieve it from the identified location. The solution is quite easy. In my case I just changed the Phone File Server Type to Memory Card. The other options would be to configure the Manager PC IP Address to reflect the location of the correct version of Manager (Making sure the IP Office can reach that PC), or to change the type to Custom and specify the IP Address of the server that contains your BIN files.
Hopefully this helps!