SNaQ Error

[Emily Watts-Whitehead]

Hello,

I am using SNaQ on simulated data, and I am occasionally encountering this error:

optimization of topology, BL and inheritance probabilities using:
 hmax = 0,
 tolerance parameters: ftolRel=1.0e-6, ftolAbs=1.0e-6,
                       xtolAbs=0.001, xtolRel=0.01.
 max number of failed proposals = 75, liktolAbs = 1.0e-6.
rootname for files: net0
BEGIN: 10 runs on starting tree (4,3,(5,(1,2):0.17001004306736592)1:0.1515317346376308)1;

main seed 1234
seed: 1234 for run 1, 2023-06-20 12:20:47.957

BEGIN SNaQ for run 1, seed 1234 and hmax 0 changed starting topology by NNI move

ERROR found on SNaQ for run 1 seed 1234: ErrorException("all four nodes to keep when extracting the quartet should be leaves: [5, 1, 4, 3]")

Because I am using multiple replicates of the simulations, it is especially confusing to me, as SNaQ will run perfectly on some replicates while giving this error on others. Has anyone encountered a similar issue, or can anyone shed light on what it means? 

Thanks!