issue on the exportation

[colomet]

Description

If i export a PDF i get a warming

Expected behaviour

Just to export

Actual behaviour

Export the book, and looks lik it works the pdf, but I have the warming in the exporting page

Steps to reproduce the problem

Just export the book

System Information

• Pressbooks mPDF: [3.0]
• Pressbooks: [4.5]
• WordPress: [4.9.1]

[bdolor]

@colomet are you still getting this error? I haven't seen it before and would like to be able to reproduce.

[colomet]

I do try, and I can not see it again. Maybe a PB update fix it. If it happen again, i will text