Hi Stuart,
The experience you get with this depends on which version of Jiwa you are using.
In 7.2.1 we changed the way of drilling down to TODO links - we used to use what's known as an asynchronous pluggable protocol (aka shell links) - which just meant that when you installed Jiwa, we added a registry entry such that links starting with jiwa: would be recognised by browsers and invoke Jiwa.exe with the URL information and launch Jiwa.exe, passing in the URL as an argument and Jiwa.exe would look to see if another Jiwa.exe was running and if so, invoke a method via a socket which knew what to do with the URL.
This had many shortcomings (like what if Jiwa was running, but connected to a different database - see
DEV-7189), so we decided to remove that way of drilling down in
DEV-7611 as part of 7.2.1. We now don't rely on the asynchronous pluggable protocol (shell link) and instead parse the URL ourselves and load up the form just like you would normally do within Jiwa.
I think what might be happening for you is your system still has the registry entries we wanted to remove which handle drilling down using a shell link.
Can you check to see if you still have the registry entries described in
DEV-7611 ? If you do still have them, remove them and try again - if that works then we obviously failed to remove those registry entries as we intended, and you should log an issue for that. If it still doesn't work, then we'll need to know where the hyperlink is failing (there are a few places which handle TODO links - is it the TODO desktop notification, listing form or TODO maintenance form) and with that information we can test and try to repro the issue.