Hi, Mykl,
Please refer to the Installation Manual embedded within the
distribution tarball (.../ck-admin/doc/Installation Manual.html).
You'll find that the relevant fully tested (MiddleWare + CK-ERP +
Webserver environment) combo.
For CK-ERP 0.31.1 and vTiger,
The fully tested combo is,
vTigerCRM 5.3.0; Kubuntu 11.10; Apache2.2.20/Mysql 5.1.58/ PHP
5.3.6)
Please ensure that your operating environment is as close to the
fully tested environment as possible.
Best Regards,
CK
PS - Because CK-ERP had not been updated for a long time. If you
are running CK-ERP against recent Middleware versions and/or
within recent versions of Webserver software, you'll bound to face
a lot of incompatible issues. If you are unable to recreate the
required (perhaps outdated) Linux processing environment, you
should really try other open source ERP software instead of
CK-ERP.