Thanks for the quick reply Mapx.
And you are likely at least partially correct...
Going back to around v21/22 I updated Iron to find 2 of my preferred extensions were no longer working. Upon troubleshooting the issue at the time I read (cannot recall 100% tho think it was on this site) that Iron would no longer support Chrome Store Extensions, as the developers considered these contrary to the improved privacy that Iron offers? Subsequently, upon the next two update attempts the situation remained the same. And between then and now I've not heard/read anything to the contrary?
Caveat: This is to the best of my recollections unless I completely misunderstood, and in which case my apologies to all concerned?
In the interim my default profile was
rendered corrupt, I've no idea why, and so I created a new one. Following which I could still not get the extensions concerned installed and working.
Cutting a very long story short...
After coming back here yesterday in search of a solution, I bit the bullet and did a clean install of Iron version 29.0.1600.1. This involved removing all Iron/*Chromium related leftovers from AppData, and manually from the windows registry.
All is now installed and working to my satisfaction- even though I cannot say exactly how or why...