7.2.0v

7.3.0v

Spectrum's version : spectrum-1.4.0-1.18.2-chaos-and-exploration
But previous Spectrum version works well (spectrum-1.3.3-1.18.2-midgame18-trinkets-brewing)

It seems Like Iris Shaders also had a problem connected to langfiles in combination with Spectrum. Maybe their bugfix helps you also to fix it?

https://github.com/IrisShaders/Iris/blob/trunk/docs/changelogs/1.2.6/full.md

I adressed the issue with https://github.com/devs-immortal/Incubus-Core 👌

Closed as resolved, thanks DaFuqs