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

--- re-building ‘easyPM_vignette_html.Rmd’ using rmarkdown
Warning in grep("\\\n$", msg) :
  input string 1 is invalid in this locale
Quitting from lines 39-50 (easyPM_vignette_html.Rmd) 
Error: processing vignette 'easyPM_vignette_html.Rmd' failed with diagnostics:
1: Input is not proper UTF-8, indicate encoding !
Bytes: 0xE3 0xA2 0x07 0x0A
2: error parsing attribute name
3: attributes construct error
4: Couldn't find end of Start Tag Citp<e3> line 904
5: PCDATA invalid Char value 7
6: Opening and ending tag mismatch: Reference line 903 and Abstract
7: Opening and ending tag mismatch: Author line 907 and ArticleIdList
8: Opening and ending tag mismatch: AuthorList line 906 and Reference
9: Opening and ending tag mismatch: ISSNLinking line 1215 and KeywordList
10: Opening and ending tag mismatch: MedlineJournalInfo line 1211 and MedlineCitation
11: Opening and ending tag mismatch: MedlineCitation line 1079 and PubmedArticle
12: Opening and ending tag mismatch: JournalIssue line 1570 and Abstract
13: Opening and ending tag mismatch: Journal line 1568 and Article
14: Opening and ending tag mismatch: Article line 1567 and MedlineCitation
15: Opening and ending tag mismatch: MedlineCitation line 1560 and PubmedArticle
16: PCDATA invalid Char value 18
17: Specification mandate value for attribute MajorTopicY
18: attributes construct error
19: Couldn't find end of Start Tag DescriptorName line 3603
20: Opening and ending tag mismatch: MeshHeading line 3602 and PubMedPubDate
21: Opening and ending tag mismatch: MeshHeadingList line 3555 and History
22: Opening and ending tag mismatch: MedlineCitation line 3358 and PubmedData
23: expected '>'
24: Premature end of data in tag PubmedArticle line 1078
25: Premature end of data in tag PubmedArticleSet line 3

--- 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_13515132_130.14.18.34_9001_1546198249_283100641_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: 0xB0 0x7A 0xBA 0x08
2: StartTag: invalid element name
3: PCDATA invalid Char value 8
4: Opening and ending tag mismatch: Reference line 969 and AffiliationInfo
5: Opening and ending tag mismatch: ReferenceList line 740 and Author
6: Opening and ending tag mismatch: AffiliationInfo line 997 and Citation
7: Opening and ending tag mismatch: Author line 993 and Reference
8: Opening and ending tag mismatch: PubmedData line 698 and ReferenceList
9: Opening and ending tag mismatch: PubmedArticle line 443 and PubmedData
10: Opening and ending tag mismatch: PubmedArticleSet line 3 and PubmedArticle
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