Undefined variable "vision" or class "vision.Ca​scadeObjec​tDetector"​.

every time i enter this code:

myFaceDetector = vision.CascadeObjectDetector;

i get this error

Undefined variable "vision" or class "vision.CascadeObjectDetector".

how do i fix this?

MATLAB R2019a

[Sreelakshmi S.B]

Check to see if you've the 'Computer Vision System Toolbox' installed by typing ver at the MATLAB command prompt.

[Tanisha Gupta]

yes 'Computer Vision System Toolbox' installed

[Qu Cao]

Try

>>restoredefaultpath

>>rehash toolboxcache

[mai shebl]

I have same error help me please,I try what you say but nothing happen

[Walter Roberson]

What shows up for

ver('vision')
which -all vision.CascadeObjectDetector