Wis. Stat. § 102.12
No claim for compensation may be maintained unless, within 30 days after the occurrence of the injury or within 30 days after the employee knew or ought to have known the nature of his or her disability and its relation to the employment, actual notice was received by the employer or by an officer, manager or designated representative of an employer. If no representative has been designated by posters placed in one or more conspicuous places where notices to employees are customarily posted, then notice received by any superior is sufficient. Absence of notice does not bar recovery if it is found that the employer was not misled by that absence. Regardless of whether notice was received, if no payment of compensation, other than medical treatment or burial expense, is made, and if no application is filed with the department within 2 years after the date of the injury or death or the date the employee or his or her dependent knew or ought to have known the nature of the disability and its relation to the employment, the right to compensation for the injury or death is barred, except that the right to compensation is not barred if the employer knew or should have known, within the 2-year period, that the employee had sustained the injury on which the claim is based. Issuance of notice of a hearing on the motion of the department or the division has the same effect for the purposes of this section as the filing of an application. This section does not affect any claim barred under s. 102.17(4).
Wis. Stat. § 102.12