Running external command line application(s). This may print messages to stdout and/or stderr.
The command(s) being run are below. These commands cannot be manually re-run as they will depend on temporary files that no longer exist.

Command: run_dada_paired.R /tmp/tmp900tiuxs/forward /tmp/tmp900tiuxs/reverse /tmp/tmp900tiuxs/output.tsv.biom /tmp/tmp900tiuxs/track.tsv /tmp/tmp900tiuxs/filt_f /tmp/tmp900tiuxs/filt_r 245 186 0 0 2.0 2 consensus 1.0 64 1000000

R version 3.4.1 (2017-06-30) 
Loading required package: Rcpp
DADA2 R package version: 1.6.0 
1) Filtering ..
2) Learning Error Rates
2a) Forward Reads
Initializing error rates to maximum possible estimate.
Sample 1 - 36004 reads in 13871 unique sequences.
Sample 2 - 142094 reads in 47168 unique sequences.
   selfConsist step 2 
   selfConsist step 3 
   selfConsist step 4 
   selfConsist step 5 
Convergence after  5  rounds.
2b) Reverse Reads
Initializing error rates to maximum possible estimate.
Sample 1 - 36004 reads in 10013 unique sequences.
Sample 2 - 142094 reads in 33948 unique sequences.
   selfConsist step 2 
   selfConsist step 3 
   selfConsist step 4 
Convergence after  4  rounds.

3) Denoise remaining samples 
4) Remove chimeras (method = consensus)
Error in isBimeraDenovoTable(unqs[[i]], ..., verbose = verbose) : 
  Input must be a valid sequence table.
Calls: removeBimeraDenovo -> isBimeraDenovoTable
In addition: Warning message:
In is.na(colnames(unqs[[i]])) :
  is.na() applied to non-(list or vector) of type 'NULL'
Execution halted
Traceback (most recent call last):
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/q2_dada2/_denoise.py", line 231, in denoise_paired
    run_commands([cmd])
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/q2_dada2/_denoise.py", line 36, in run_commands
    subprocess.run(cmd, check=True)
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/subprocess.py", line 418, in run
    output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['run_dada_paired.R', '/tmp/tmp900tiuxs/forward', '/tmp/tmp900tiuxs/reverse', '/tmp/tmp900tiuxs/output.tsv.biom', '/tmp/tmp900tiuxs/track.tsv', '/tmp/tmp900tiuxs/filt_f', '/tmp/tmp900tiuxs/filt_r', '245', '186', '0', '0', '2.0', '2', 'consensus', '1.0', '64', '1000000']' returned non-zero exit status 1.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/q2cli/commands.py", line 274, in __call__
    results = action(**arguments)
  File "</opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/decorator.py:decorator-gen-442>", line 2, in denoise_paired
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/qiime2/sdk/action.py", line 231, in bound_callable
    output_types, provenance)
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/qiime2/sdk/action.py", line 365, in _callable_executor_
    output_views = self._callable(**view_args)
  File "/opt/conda/envs/qiime2-2019.1/lib/python3.6/site-packages/q2_dada2/_denoise.py", line 246, in denoise_paired
    " and stderr to learn more." % e.returncode)
Exception: An error was encountered while running DADA2 in R (return code 1), please inspect stdout and stderr to learn more.