You can correct any errors regardless of any contractual provisions. In the absence of contractual provisions, you can perform additional changes to the software.

So if there is a bug, you can fix it yourself, whether or not the provisioning company has a(n) (un)paid plan for you that fixes it. This makes sense - otherwise you could once in a while let a bug "slip" to production intentionally and then ransom your users for more payment.

The relevant part of the law:

> Whereas this means that the acts of loading and running necessary for the use of a copy of a program which has been lawfully acquired, and the act of correction of its errors, may not be prohibited by contract; whereas, in the absence of specific contractual provisions, including when a copy of the program has been sold, any other act necessary for the use of the copy of a program may be performed in accordance with its intended purpose by a lawful acquirer of that copy;