Advice for the R-package of lme4

Thank you for your advice.
I appreciate your kindness.
Very sorry to bother you while you are busy.

I remembered making a backup of all R-packages before late April 2021.
Therefore, I loaded (downgraded) all packages and ran the program.
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Meanwhile, I have been in trouble of which the values in the output are
slightly different between late April 2021 and August 2021. The source
code, R environment, and csv files are the same (R-3.6.1 in Windows 10).
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For a different dataset made up before late April 2021, I could reproduce
the results.
So, the reason that I could not reproduce the results using the dataset,
which I posted you, seems that some problems have occurred in the period,
which I did not make a back up, such as OS update or consistency with other
packages.

I don't want to cause you any more trouble, so I'll do some more research
on my own for solving. Thank you very much.

Best regards

2021?8?27?(?) 10:48 Ben Bolker <bbolker at gmail.com>:

   These are basically harmless.

  lmerTest substitutes its own version of `lmer`. This is often
confusing, but when it works it provides a seamless user experience
(i.e., people load lmerTest and everything works the same but they also
get denominator degrees of freedom and p-values in their summary tables).

   It also defines its own version of 'step'.  You can see the help for
`lmerTest::lmer` or `lmerTest::step` for an explanation of why these
functions are masked.


--
Dr. Benjamin Bolker
Professor, Mathematics & Statistics and Biology, McMaster University
Director, School of Computational Science and Engineering
Graduate chair, Mathematics & Statistics