So I purchased unraid many years ago and ran it for a while, but then have not used it in a few years. I booted back up my old system from the flash drive and everything works fine, it is version 6.1.9. 
When i goto plugins and "check for updates" it shows 6.5.3 available. I click update and i get 

"plugin: updating: unRAIDServer.plg
plugin: downloading: https://s3.amazonaws.com/dnld.lime-technology.com/stable/unRAIDServer-6.5.3-x86_64.zip ... failed (Invalid URL / Server error response)
plugin: wget: https://s3.amazonaws.com/dnld.lime-technology.com/stable/unRAIDServer-6.5.3-x86_64.zip download failure (Invalid URL / Server error response)"

If i try to access those urls via browser i get:

<Error>

<Code>AccessDenied</Code>

<Message>Access Denied</Message>

<RequestId>A9375A826851E79A</RequestId>

<HostId>2BY0xDu3FmHr8P/bZRkqNi/5+Dl7zVyGDeOa2kduBtgOWYMNBpgYb5/0mbkLBGXQDo1w7Jp2qMQ=</HostId>

</Error>

 

How should i go about upgrading ? 

Thanks for any help in advance. 

 

Make a backup of your flash drive. You will have to prepare flash as a new install and copy the config folder from your flash backup.

 

Before attempting the upgrade, study this thread to see if there is anything you need to take care of coming from such an old version:

 

1 minute ago, trurl said:

prepare flash as a new install

Or you can download the latest stable version from the Download page and just copy all the bz* files from that zip to the top folder of your flash drive.

Thank you. That worked great.