heatmap.2 does not show the color key

Question

My codes:

heatmap.2(cor_r, cellnote = sym2, notecol = "black", key = T, keysize = 0.5, key.par = list, Rowv = as.dendrogram(hclust.signs), Colv = as.dendrogram(hclust.areas), trace = "none", margins = c(10,10), col = my_palette, breaks = col_breaks, lmat=rbind(4:3,2:1))

Two problems:

1. No color key is shown.
2. When I rerun the codes, RStudio is broken down.

Answer 1

Though don't know why, "breaks = col_breaks" is the reason. Deleting this part will get everything right.