Crystallisation is likely in high concentrations of CBD.
Think of it like quality honey. The hemp seed carrier oil is saturated in quality, high strength CBD.
Variations in temperature are likely to cause crystallisation, depending on how cold and where the bottle is stored.
If your product crystallises, the sealed bottle should be kept upright and immersed in hot water at a temperature of 70°C for several minutes until the extract has returned to a liquid. Give it a good shake to combine the CBD with the hemp seed oil before use.