I received an error message when inserting the code

There is a number of reasons why a voucher's code could not be working properly:

1- The codes are valid for a specific period of time, after which they will no longer be available: "The code you entered has expired! Be faster next time!"

2- Codes can usually be used for a limited number of users. When this number is reached, the code cannot be used any further: "You have reached the maximum number of times this voucher can be used"

3- Certain vouchers are Welcome Vouchers and can only be used before using others.
“Oops! Remember that Welcome Codes can only be used once"

4- Some codes can only be used if you've previously purchased or signed up for a specific plan. "To use this voucher you have to purchase the corresponding ticket"

5- Some codes can only be used in certain cities
"Check that you're in the right city to use this voucher"

6- When the app needs to be updated to the latest version, codes cannot be used. "Please update the app to the latest version to use your codes"

7- When one device has more than one Fever account logged in, it is not possible to use codes and vouchers

8- Los códigos solo se pueden utilizar una vez. Si introducimos el mismo código dos veces nos dará error.
"This coupon has already been used"