L.C. Briand and S. Morasca and V.R. Basily
Only because space or a dot is missing after firstnames.
Also remove dot at the end of the warning message: Names are not in the standard BibTex format.
This is an issue I would like to see been solved. Any entry I add using Medline has this problem with missing dots. Why don't you have the program add them? If it can recognize the missing dots, I guess it would be simple to add them, too.
Right-click > Normalize to BibTeX name format adds the missing space (and reorders the name parts).
I'm actually not sure if we should change this behavior. As far as I'm aware, the space should be there by convention...
I did the rightclick > Normalize but the error (?) remains. It is only gone when the program is closed and reopened.
JabRef 5.0-dev--snapshot--2018-07-12--master--dd9b22911
Windows 7 6.1 amd64
Java 1.8.0_172

The BibTeX standard seems to be that there should be a space after the dot. Hence, the check is ok like it is right now.
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Right-click > Normalize to BibTeX name format adds the missing space (and reorders the name parts).
I'm actually not sure if we should change this behavior. As far as I'm aware, the space should be there by convention...