I've found Blender very fussy about saving textures centrally - still not sure what needs to be set up in order to re-use textures, but yeah - I get that pink colour a lot... :blink:

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks