[1] "Matrix is empty!!" Error in strsplit(LABEL, " ") : non-character argument

[GreenAnalytics]

Hi, I have followed all the steps as per the github tutorial, but I am facing a problem when trying to generate the NetMatrix from the file uploaded. I run the following command and the error shows:

NetMatrix <- biblioNetwork(M, analysis = "co-citation", network = "references", sep = ";")
[1] "Matrix is empty!!"
Error in strsplit(LABEL, " ") : non-character argument

packageVersion("bibliometrix")
[1] ‘4.1.4’

R.Version()$version.string
[1] "R version 4.3.2 (2023-10-31)"

M.csv