Despite following a good number of tutorials on here and elsewhere, I havent been able to get wkhtmltopdf to work properly with odoo 12 on Debian 9.

I'm using the bitnami odoo 12 stack; wkhtmltopdf 0.12.5; Debian 9 running on a google compute engine VM. wkhtmltopdf seems to be working from the command line.

The error on odoo is: 

Wkhtmltopdf failed (error code: -11). Memory limit too low or maximum file number of subprocess reached. Message : b'Fontconfig error: Cannot load default config file\n'

On /var/log/syslog there's the following error:

odoo-1-vm kernel: [6226528.320769] wkhtmltopdf[9660]: segfault at 7f98275f1bc0 ip 00007f98275f1bc0 sp 00007fffb5a9cc38 error 15 in libssl.so.1.1[7f98275ee000+4000]

Thank you for any help or pointers to a solution.