Error in executing Demo files of Maaslin2

[Selva Sankar]

HI

I am new to Maaslin2. I was trying to run through Rstudio using demo data. But i got the following error. can anyone help me to figureout this issue. Thank you.

> fit_data <- Maaslin2(example1_features, example1_metadata, output = "output")
[1] "Warning: Deleting existing log file: output/maaslin2.log"
2019-02-19 16:24:35 INFO::Writing function arguments to log file
2019-02-19 16:24:35 INFO::Verifying options selected are valid
2019-02-19 16:24:35 INFO::Determining format of input files
2019-02-19 16:24:35 INFO::Input format is data samples as rows and metadata samples as rows
2019-02-19 16:24:35 INFO::Formula for fixed effects: expr ~  X. + Metadata1 + Metadata2 + Metadata3 + Metadata4 + Metadata5_TP + Metadata6 + Metadata7 + Metadata8 + Metadata9_TP + Metadata10
2019-02-19 16:24:35 INFO::Running selected normalization method: TSS
Error in FUN(newX[, i], ...) : invalid 'type' (character) of argument
In addition: Warning message:
In vegan::decostand(features_norm, method = "total", MARGIN = 1,  :
  input data contains negative entries: result may be non-sense