At the left navbar there are not all icons. There are just 3 - e. g. overview. There are some more icons missing (e. g. overview planning or skipping a booking). Even if there is no icon the function is working! Version 4.6.6 (with a new Kubuntu 16.04 Installation) Reproducible: Always Steps to Reproduce: 1. Open KMymoney 2. 3.
There are definitely more icons available in 5.0 version, so marking it as fixed. With your version you can use oxygen icon theme to solve your problem.