Add On Names Dont Display

we are getting a strange error when we click on the View Addon and open all addon tab

http://prntscr.com/b01vnw

There are couple of addons for which names and other info are not displayed. Any idea what could cause this issue ?

Clear cache & check language file exist of addons.

Clear cache & check language file exist of addons.

thanks that fixed the issue

thanks that fixed the issue

Was the reason just in cache?

Was the reason just in cache?

No actually i found the files missing from the var > lang > en folder. Added them from backup and it worked.

Lesson learnt : Dont delete the files in var folder.

No actually i found the files missing from the var > lang > en folder. Added them from backup and it worked.

Lesson learnt : Dont delete the files in var folder.

Thank you for the clarification. The only directory which can be completely deleted at anytime is var/cache