An unknown error has occurred adobe illustrator | How to fix this problem ? 

Hi in this short video i recorded a problem and its solution that i faced using adobe illustrator .
This video is about : Adobe illustrator page not opening , Adobe illustrator document not opening , adobe illustrator file not opening and its solution.
In my case adobe illustrator was not opening file and new document and it was showing a message : An unknown error has occurred.
This video is about these questions:
How to solve / fix An unknown error has occurred adobe illustrator ?
How to fix problem of an unknown error has occurred in Illustrator ?
How to fix problem of an unknown error has occurred in Illustrator ?
How i fixed it , you can watch it in this video.