Nothing wrong with the engine.

Didn’t the Sapphire suffer blade rubbing in some conditions, also under the impression that the Sapphire was realised early on that it wasn’t as ‘developable’ as the Avon would be – and clearly was in the 200/300?

The Sapphire (ASX, inherited from Metrovick F.9) did feature an annular combustion chamber from the start, which was a more modern layout, and which the Avon switched to from the 200 series, and ASM did use a superior fuel atomiser design in its turbojets.
Have also seen it written that the Rolls Royce obtained use from ASM for their superior compressor design.

Interesting that the Americans choose the Sapphire to develop as the J-65 though, (inc fitment in their Canberra versions), rather than the Avon.

Good to hear that this Hunters’ future appears to be safe.