This one is a strange one for ZXing and is actually just about renaming the folder.
STEP 01:
When you install the library, it appears with folder name zxing4p3-v3.4
Now, change it to just zxing4p3
STEP 02:
Go to the example called decodePImage>data and copy the font ArialMT-14.vlw
Create a ‘data’ folder in the generateQRCode example. There is no ‘data’ folder present here.
Then rename ArialMT-14.vlw to ArialMT-18.vlw
STEP 03:
Run sketch.
Hopefully this should help. Cheers! 