Try For Baby Not Available
Product: The Sims 4 Platform:PC Which language are you playing the game in? English How often does the bug occur? Every time (100%) What is your current game version number? 1.108.335.1020 What ...
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Just in case I'll ask: what are these sims' gender settings? You can access those by clicking on the three dots button below the gender selection.
In particular, make sure that one of the Sims will be able to Become Pregnant and the other one will be able to Get Others Pregnant.
If you open your Sim's Simology panel, you can easily view and edit all the gender settings by clicking the Enter Create a Sim button under Relationship Preferences.
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