After a bit of back and forth with Patrick, the URL generated by the Kobo Utilities plugin for my Sage seems to work when I plug it into Firefox, Edge or Chrome. Two tests were run:
One using
https://api.kobobooks.com/1.0/Upgrad...N7781900008423 which returned:
Code:
<UpgradeCheckResult xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WebAPI.APIModel">
<Data i:nil="true"/>
<ReleaseNoteURL i:nil="true"/>
<UpgradeType>None</UpgradeType>
<UpgradeURL i:nil="true"/>
</UpgradeCheckResult>
A second test modifying the URL to say I was using 4.35.20400 gave the following which returned the link to 4.37.21533.
https://api.kobobooks.com/1.0/Upgrad...N7781900008423
Code:
<UpgradeCheckResult xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WebAPI.APIModel">
<Data i:nil="true"/>
<ReleaseNoteURL>https://api.kobobooks.com/1.0/ReleaseNotes/148</ReleaseNoteURL>
<UpgradeType>UpgradeRequired</UpgradeType>
<UpgradeURL>https://kbdownload1-a.akamaihd.net/firmwares/kobo8/Jun2023/kobo-update-4.37.21533.zip</UpgradeURL>
</UpgradeCheckResult>
I went back to calibre 6.10.0 and 6.15.1 and got the same results. The connection seems to go through Cloudflare which has been unhappy before with various user agent values.