The Nebraska Construction Lien Act provides that your lien will be effective for two years after recording of the lien. If you do not institute judicial proceedings within those two years, your lien will become void. This does not mean that you do not retain a claim against the property owner, it just means that you will have to obtain a judgment before you can again attach the property.
There is, however, a twist to how long your lien will remain effective. If the owner makes a written demand that you institute a judicial proceeding within thirty days, the lien will lapse unless within thirty days of the demand you file suit or record an affidavit stating that the total contract price is not yet due under the contract.
For owners, this can be a tremendous tool to eliminate liens that were frivolously filed. It should also be a warning to contractors that you may have a very short window in which to enforce your lien.
Liens are a great way to preserve your interest in the property, but make sure you enforce your lien in time.