Hi @ScottW ,
What @andresrcs is asking for is, rather than posting screenshots of your code/output, if you can can provide the code you're running (e.g. as text, you can copy it in to here in between two sets of ``` to format it as code). Specifically, it would be helpful to create an example of your code that we can reproduce on our own computers. That post that was linked to (FAQ: How to do a minimal reproducible example ( reprex ) for beginners) will show you how to make a redproducible example.
In the mean time, I can suggest that you just don't need to use GBR$... inside a pipeline using dplyr, you can just use the variables themselves. So your code would become:
GBR %>%
group_by(X.Year) %>%
summarise(Rainfall = sum(Rainfall..mm.))