Your question is a little confusing. If you have filed in WI, WI law must be followed. If the WI case was dropped and you re-filed in IL, there is no time limit, (within reason, as the case will be dismissed if there is no action for a very long period of time) but the Summons is only good for 30 days. If the Respondent is not served within 30 days, then a new, Alias Summons must be issued. Cases cannot be pending simultaneously in 2 different states.
The summons must be served within 30 days of the date it is issued. Divorce proceedings should not be pending in two states simultaneously. If the Wisconsin case was previously dismissed, then the Illinois court may have jurisdiction. There is technically not a specific time limit for having the summons issued and served, though if you fail to do so for a significant length of time, the court is likely to dismiss your case.
It is important to establish who filed, then which petition is first and whether both petitions are pending at the same time. Also, if service was successful in Wisconsin but not in Illinois there is a danger that the divorce will proceed in Wisconsin and both parties have to litigate it in that State. You will find it to your advantage to take all the paperwork to a local lawyer if just for a consultation and to find out next best steps.
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