Getting automatically removed issue for cordova plugins

i am getting a problem with cordova plugin as they are automatically removed from the project when project is run for iOS, like camera , twitter plugins etc.
getting error that plugin is not installed, and app crashes at that time.

i confused to get rid from this problem, i already spent more hours on this to search it. please help me for this.

What is your ionic info output?

What do you mean by “removed”? Entries deleted from package.json and config.xml?

What exact error where after you install the app by runnign what command?