From what you allege, it would appear that Liberty cannot succeed in a lawsuit against you, by signing the agreement years after you originally signed and sent it to Liberty -- because you relied to your detriment on Liberty's silence and you acted as if you were in a franchise during the entire five years of the contract's duration -- under the assumption that Liberty accepted your changes. So, either, you had an agreement on your modified terms, or you had no agreement at all -- in either case, the agreement expired before you sold the business to a third party, and you are not liable to Liberty for anything.
Regardless, you will have to defend that the contract is expired, and that you were not under any obligation to Liberty at the time that you sold your business.
Concerning your suing Liberty, assuming you can successfully defend, you may have a claim for wrongful institution of civil proceedings/malicious prosecution
, if it is shown that Liberty's lawsuit is entirely without merit. And, if you were damaged by the various claims made by the government and others against Liberty during the course of either the first or second contract, then you may have a claim of breach of contract
, in that Liberty failed to maintain a reasonable level of good will in its product, which is the principal thing that you were contracting for -- i.e., favorable market exposure. Criminal complaints
are not actionable by a private party. So, while you can complain to government, you cannot recover damages from the defendant.
I think I've covered your question. Please let me know if I can clarify anything or provide further assistance.
Hope this helps.