I was having the same issue, and I managed to fix it by converting my PNG from a 24-bit to an 8-bit file.
Indeed, TCPDF can be finicky about the png being fed to it. Please try the latest build of the plugin, which includes an update to the latest TCPDF (6.2.6).
Cheers
Lewis
Hi, I have the same problem with PNG logos not showing on the rendered PDF. JPGs work.
However, these logos worked in the previous version of WP Post to PDF Enhanced (1.0.5)). Just ran the update today, and needless to say, my client is pissed.
Btw, why not use the header image already uploaded for the website, or allow uploading in the plugin?
Looks like it has something to do with the Alpha channel. If I flatten the PNG it will show up in the rendered PDF. Not a sustainable solution though. Why have transparent PNG’s stopped working?
I too have the same problem. I have tried PNG 24 / 8. No go.
