Kotzig's cyclic tree decomposition conjecture

Let $T$ be a tree with $n+1$ vertices, and identify the vertices of $K_{2n+1}$ with the integers modulo $2n+1$. A cyclic decomposition into copies of $T$ consists of the cyclic shifts of one copy of $T$ forming an edge decomposition. Ringel--Kotzig conjecture. For any $(n+1)$-vertex tree $T$, the complete graph $K_{2n+1}$ can be cyclically decomposed into copies of $T$. This strengthens Ringel's conjecture by requiring the decomposition to arise from cyclic shifts, and remains open in the source's discussion.