"You are downgrading the VAT invoice software" means that the version of the VAT invoice software (tax Ukey version) you are using is too low.

People's Republic of China (PRC) State Taxation Administration of The People's Republic of China stipulates that the use of VAT fiscal invoicing software must meet certain version requirements. The software version is too low, and it can only be invoiced normally if it is upgraded to at least version 33.0. If the software version is too low, it will be regarded as a degraded version and the related functions of the software will be prohibited.