German "Gewährleistung" is similar to warranty, but regulated through law.
The statutory "Gewährleistung" is generally 24 months, and refers to errors that were present from the beginning. If an error occurs within the first 6 months, the legislator automatically assumes an initial error and thus is covered by the "Gewährleistung".
If an error occurred after the period of 6 month, the customer must proof that it is an initial error (the so-called burden of proof).
If this proof is not possible, the legislature does not think this an initial error and thus not a damage covered by the "Gewährleistung".