Salt failed to create the expected texture and dissolved into the watercolour. What is the most likely cause?

Correct answer: The surface was excessively wet

The governing technique is the salt texture effect in a watercolour wash. Salt should be sprinkled when the painted surface is damp enough for the crystals to draw moisture and pigment, but not so wet that they simply dissolve. On an excessively wet wash, water surrounds the salt and prevents a clear crystal pattern from forming. A slightly damp surface is generally more suitable, while dry paint gives little opportunity for the salt to move moisture and pigment.