DakT
Home / Visualization problem in spanish language
GitHubRulesOK
Not uncommon since the graph may have been inserted by one app into the page of another app without the font corectly transfered. You would need to post the file at Issues · sumatrapdfreader/sumatrapdf · GitHub however it is probably down to MuPDF code library so first check todays MuPDf update You can easily use a portable version from https://www.sumatrapdfreader.org/prerelease if the letter appears, then there no need to open an issue or upload the pdf but if not fixed then the sample is needed to raise a bug report.
DakT
Prerelease version works well, the letter appears¡¡¡. Thank you very much ¡¡¡¡¡