Optical errors decrease the performance of solar concentrators. Here we assess the sensitivity of a novel 2-stage dish concentrator against optical errors. We use Monte Carlo ray-tracing, probability statistics, and optical geometrical principles in the analyses. The key finding is that the novel concentrator can reach a high radial distribution of flux concentration and high optical efficiency over a range of optical errors. Compared to a traditional 2-dish concentrator, the performance was clearly better. The results are in good agreement with results from the TracePre tool. The results also imply improved tracking stability with the novel 2-stage dish concentrator. (C) 2018 Elsevier Ltd. All rights reserved.