Fatal error: Class 'Projax' not found

[viz]

I installed mantisbt-1.2.19 on windows.while reporting issue, system display following error.

"Fatal error: Class 'Projax' not found in C:\xampp\htdocs\mantisbt\core\projax_api.php on line 34"

[viz]

FYI.
Fatal appears for 1.2.19 but its working fine for 1.2.17

[atrol]

To follow up https://www.mantisbt.org/bugs/view.php?id=19658