Wizard not responding

[allankay]

Several conversion attempts of any PDF into MOBI/AZW3 has resulted in illegible page text. Discovered how to run Search Replace to remove unwanted formats with regular expressions. A online help document says to first press the Wizard button to see the coding of the PDF causing problems. Every time I do this, Calibre goes into "Not Responding" and Windows 10 popup asks to close it (Calibre). Have fresh install of Calibre v.5.14 on Windows 10 fully updated. Restarted several times and even ran the Update on Calibre, all to no good end. Please give me ideas on what I missed here. Thanks.