argument is of length zero error

[ysapolovych]

Trying to work with european influence rdf library (128 articles in pdf) https://www.dropbox.com/sh/cjofpewdi6mgdat/AAA4-hngX1s361ekI6Alir7ta/European%20Influence%20-%20Zotero/European%20Influence?dl=0

On an attempt to upload rdf with a recent ITMS version I get this:

Loading required package: viridisLite
Warning: Error in if: argument is of length zero
Stack trace (innermost first):
116: zotero_rdf [zotero.R#44]
115: reactive:zoteroData [C:\ITMS\HCSS-Rizzoma-master/server.R#165]
104: zoteroData
103: reactive:extractZoteroTerm [C:\ITMS\HCSS-Rizzoma-master/server.R#241]
92: extractZoteroTerm
91: reactive:zotero_content [C:\ITMS\HCSS-Rizzoma-master/server.R#297]
80: zotero_content
79: renderUI [C:\ITMS\HCSS-Rizzoma-master/server.R#305]
78: func
77: origRenderFunc
76: output$print_zotero
1: shiny::runApp

Path is C:\Users\Yevhenii\Documents\ITMS test\5th, all pdfs in the 'files' subfolder

You may also look on rizzoma: https://rizzoma.com/topic/6b33d71cb66f8fd8c3f39df3b386c851/0_b_8nfl_8cp16/