@elreigh
Without more information it hard to figure out what might be causing this error, but I will try to help you. In your 'playerAttachment' you have set 'retainCapitalProduceNumber', have you also tried setting 'retainCapitalNumber' to zero?
Also there are some 'rulesAttachment' settings that might help 'productionPerXTerritories', 'placementAnyTerritory', 'placementAnySeaZone', 'placementCapturedTerritory', 'placementPerTerritory', 'maxPlacePerTerritory' and 'unlimitedProduction'.
And then there are some '<property>' settings:
<property name="Production Per X Territories Restricted" value="true" editable="false">
<boolean/>
</property>
<property name="Production Per Valued Territory Restricted" value="false" editable="false">
<boolean/>
</property>
<property name="Unit Placement Per Territory Restricted" value="true" editable="false">
<boolean/>
</property>
<property name="Place in Any Territory" value="true" editable="false">
<boolean/>
</property>
<property name="Give Units By Territory" value ="false" editable="false">
<boolean/>
</property>
<property name="More Constructions with Factory" value="false" editable="false">
<boolean/>
</property>
<property name="More Constructions without Factory" value="false" editable="false">
<boolean/>
</property>
<property name="Unlimited Constructions" value="false" editable="false">
<boolean/>
</property>
Sorry I can't be of more help, but I hope this gives you some hint on where to look.
Cheers...