I installed the plugin and, there was the invalid header error which was an easy fix by adding the!W3C code as suggested above.
ខ្ញុំបានដំឡើងកម្មវិធីជំនួយនិង, មានកំហុសដែលមិនត្រឹមត្រូវបឋមកថាគឺជាការងាយស្រួលជួសជុលដោយបន្ថែមនេះ!W3C code as suggested above.