Fusion has a system for caching often used and seldom changed items on each client computer to save network traffic for common operations. This cache is sometimes referred to as the Master Cache and it contains information about drugs, inputs, colors, breeds, pens, rations, and much more.
In the normal course of operation, if you change something that is also in the cache, Fusion will make sure that every other computer updates its cache within about 10 seconds. This actually includes your own computer which explains why after changing something like the name of an ingredient, your own computer may not know about the change for several seconds.
Normally this process works just fine and you don't even need to know that it is happening. However, is some odd circumstances a cache on a computer may become corrupt. You can force a computer to refresh its entire cache by going to Fusion Admin → Utilities → Force Cache Update. If you find that you have to do this on a regular basis, please notify us so we can look into the issue.