the fixer has likely 'sulphated' if it is a liquid concentrate - look for a layer of yellow sulphur smelling stuff in the bottom of the bottle when it is openned if it is not translucent and visible from the closed bottle/jug.
If the powders are mixed formula, then there is the possibility that the developer agents may have oxidized. Look for 'pepper' spots amongst the salt - most developer photo chems are white to light grey when fresh, and turn brown/black with age. If they are individual components of chemistry, ie carbonate, suplite, bromide, etc. then only the developer agents are at risk.
If some chemical was once anhydrous it may be by now mono or whatever else it naturally picks up water molecules as - it is still usable, you just need to account for the water that is coming along for the ride when you weight it out