Steps to reproduce:
1. create a new smart variable with parameter type integer and a matcher with the value 'abc'
2. try to save the puppetclass

Expected result: tab becomes red, next to value an error message "is invalid integer"

Actual result: the variable disappears and the puppetclass can't be saved

Workaround for now: save the puppetclass when the variable is empty (only parameter, type and default value) and then edit.
When the variable is updated the validations are shown correctly.