Error(s) in re-building vignettes:
  ...
duplicated vignette title:
  ‘Retrieving and Analyzing PubMed Records via easyPubMed’

--- re-building ‘easyPM_vignette_html.Rmd’ using rmarkdown
Quitting from lines 39-50 (easyPM_vignette_html.Rmd) 
Error: processing vignette 'easyPM_vignette_html.Rmd' failed with diagnostics:
1: expected '>'
2: Opening and ending tag mismatch: DescriptorName line 2527 and Descri
3: Opening and ending tag mismatch: MeshHeading line 2526 and Reference
4: Opening and ending tag mismatch: MeshHeadingList line 2466 and PubMedPubDate
5: Opening and ending tag mismatch: MedlineCitation line 2285 and History
6: Opening and ending tag mismatch: PubmedArticle line 2284 and PubmedData
7: Opening and ending tag mismatch: PubmedArticleSet line 3 and PubmedArticle
8: Extra content at the end of the document

--- failed re-building ‘easyPM_vignette_html.Rmd’

--- re-building ‘easyPM_vignette_pdf.Rmd’ using rmarkdown
Warning in for (i in seq_len(n)) { :
  closing unused connection 5 (https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&WebEnv=NCID_1_9062129_130.14.18.34_9001_1546106805_1121234082_0MetA0_S_MegaStore&query_key=1&retstart=0&retmax=500&rettype=null&retmode=xml)
Quitting from lines 39-50 (easyPM_vignette_pdf.Rmd) 
Error: processing vignette 'easyPM_vignette_pdf.Rmd' failed with diagnostics:
1: Input is not proper UTF-8, indicate encoding !
Bytes: 0x88 0x43 0x70 0x3A
2: expected '>'
3: Opening and ending tag mismatch: Reference line 999 and RefeP
4: Opening and ending tag mismatch: ReferenceList line 740 and AffiliationInfo
5: Opening and ending tag mismatch: PubmedData line 698 and Author
6: error parsing attribute name
7: attributes construct error
8: Couldn't find end of Start Tag A line 1026
9: Opening and ending tag mismatch: PubmedArticle line 443 and Reference
10: Opening and ending tag mismatch: PubmedArticleSet line 3 and ReferenceList
11: Extra content at the end of the document

--- failed re-building ‘easyPM_vignette_pdf.Rmd’

SUMMARY: processing the following files failed:
  ‘easyPM_vignette_html.Rmd’ ‘easyPM_vignette_pdf.Rmd’

Error: Vignette re-building failed
Error: Duplicate vignette titles
Execution halted