Error in data_prep(..) about ancombc HOT 4 CLOSED

Error in tapply(present_table[i, ], group_data, function(x) mean(x, na.rm = TRUE)) : 
  arguments must have same length
In addition: Warning message:
In data_prep(phyloseq, group, zero_cut, lib_cut, global = global) :
  The multi-group comparison will be deactivated as the group variable has < 3 categories.

library(dplyr)
library(nloptr)
library(ANCOMBC)

out = ancombc(phyloseq = ps, formula = "diet",
              p_adj_method = "holm", zero_cut = 0.90, lib_cut = 1000,
              group = "diet", struc_zero = TRUE, neg_lb = FALSE,
              tol = 1e-5, max_iter = 100, conserve = TRUE,
              alpha = 0.05, global = TRUE)

otu_mat = as(otu_table(ps), "matrix")
meta = as(sample_data(ps), "data.frame")
tax_mat = as(tax_table(ps), "matrix")
OTU = otu_table(t(otu_mat), taxa_are_rows = TRUE)
META = sample_data(meta)
TAX = tax_table(tax_mat)
ps2 = phyloseq(OTU, META, TAX)
out = ancombc(phyloseq = ps2, formula = "diet",
              p_adj_method = "holm", zero_cut = 0.90, lib_cut = 1000,
              group = "diet", struc_zero = TRUE, neg_lb = FALSE,
              tol = 1e-5, max_iter = 100, conserve = TRUE,
              alpha = 0.05, global = TRUE)