Error in augur,

augur refine is using TreeTime version 0.8.1
Traceback (most recent call last):
File “/home/mahan/miniconda3/envs/nextstrain/bin/augur”, line 10, in
sys.exit(main())
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/main.py”, line 10, in main
return augur.run( argv[1:] )
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/init.py”, line 75, in run
return args.command.run(args)
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/refine.py”, line 206, in run
tt = refine(tree=T, aln=aln, ref=ref, dates=dates, confidence=args.date_confidence,
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/refine.py”, line 36, in refine
tt = TreeTime(tree=tree, aln=aln, ref=ref, dates=dates,
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/treetime.py”, line 34, in init
super(TreeTime, self).init(*args, **kwargs)
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/clock_tree.py”, line 83, in init
self._assign_dates()
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/clock_tree.py”, line 130, in _assign_dates
raise MissingDataError(“ERROR: ALMOST NO VALID DATE CONSTRAINTS”)
treetime.MissingDataError: ERROR: ALMOST NO VALID DATE CONSTRAINTS
[Sat Apr 3 17:42:58 2021]
Error in rule refine:
jobid: 4
output: results/global/tree.nwk, results/global/branch_lengths.json
log: logs/refine_global.txt (check log file(s) for error message)
shell:

    augur refine             --tree results/global/tree_raw.nwk             --alignment results/global/aligned.fasta             --metadata data/1617434555337.metadata.tsv             --output-tree results/global/tree.nwk             --output-node-data results/global/branch_lengths.json             --root Wuhan/Hu-1/2019 Wuhan/WH01/2019             --timetree                          --clock-rate 0.0008             --clock-std-dev 0.0004             --coalescent skyline             --date-inference marginal             --divergence-unit mutations             --date-confidence             --no-covariance             --clock-filter-iqd 4 2>&1 | tee logs/refine_global.txt

    (one of the commands exited with non-zero exit code; note that snakemake uses bash strict mode!)

Logfile logs/refine_global.txt:
augur refine is using TreeTime version 0.8.1
Traceback (most recent call last):
File “/home/mahan/miniconda3/envs/nextstrain/bin/augur”, line 10, in
sys.exit(main())
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/main.py”, line 10, in main
return augur.run( argv[1:] )
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/init.py”, line 75, in run
return args.command.run(args)
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/refine.py”, line 206, in run
tt = refine(tree=T, aln=aln, ref=ref, dates=dates, confidence=args.date_confidence,
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/augur/refine.py”, line 36, in refine
tt = TreeTime(tree=tree, aln=aln, ref=ref, dates=dates,
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/treetime.py”, line 34, in init
super(TreeTime, self).init(*args, **kwargs)
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/clock_tree.py”, line 83, in init
self._assign_dates()
File “/home/mahan/miniconda3/envs/nextstrain/lib/python3.9/site-packages/treetime/clock_tree.py”, line 130, in _assign_dates
raise MissingDataError(“ERROR: ALMOST NO VALID DATE CONSTRAINTS”)
treetime.MissingDataError: ERROR: ALMOST NO VALID DATE CONSTRAINTS

Shutting down, this might take some time.
Exiting because a job execution failed. Look above for error message
Complete log: /mnt/c/Users/Mahan/Desktop/ncov/.snakemake/log/2021-04-03T174249.033605.snakemake.log

please help me for this error

Somehow, augur refine/treetime doesn’t find enough dates for the sequences in your tree.

this can happen if the taxon names in your tree and sequences don’t match the names in your metadata file. This is the first place I would start to look.