After upgrade, I can't generate pdf letters for printing. How can I enable wkhtmlpdf to handle pdf conversion?
The fix was to uninstall/reinstall sumfields! However, I had to manually delete row/drop tables (value_sumfields and custom_groups) in order to "clean install" sumfields. Still don't know why, but my instance was buggy. The usual uninstall/install procedure in the extensions manager didn't work for me. Talked to Jamie McClelland and he confirmed that I could/should manually make changes to the tables and then reinstall 3.1.1 of sumfields. NOTE: I had originally assumed that the problem had to do with wkhtmltopdf and so started down a bunny trail. For some reason upgrading from 4.7.22 to 4.7.29 AND having sumfields enabled AND using alternate pdf generator caused/revealed the problem on my instance. I will continue to investigate this, but I want to give a big shout out to Aidan at Squiffle and to Jamie at Progressive Tech Project for sticking with me.