Inviting parents in Norway

Hi everyone, I am a Filipina married here in Norway in court house and will have church wedding in Poland in September and would like to invite my parents here in Norway and we will guarantee them too. unfortunately my parents marriage certificate has a wrong entry and they tried to fix and correct it but it took so long for my country to do so, I don't know why, it was really depressing and frustrating like they started to fix it last January and until now it's hasn't done. The agency correcting the error said that it will be fixed probably end of August and we our plan is they will travel here on September 7. It says in the checklist of requirements that they need PSA marriage certificate and/or birth certificate of your children. Since they can't provide the marriage certificate, they will only give my birth certificate then. Does it and/or means either or both documents can be provided? Or does can affect their application if they can't provide their marriage certificate? Thank you in advance!