message: add an undefined check
diff: @@ -281,6 +281,9 @@ export function parseSyncTex(pdfsyncBody: string) : PdfSyncObject {
  width,
  page: currentPage.page
  }
  + if (elem.file === undefined) {
  + continue
  + }
  if (blockNumberLine[elem.file.path] === undefined) {
  blockNumberLine[elem.file.path] = {}
  }
  