Ugh...
Back again. Nothing has worked for me. I tried the "cataract to glaucoma" test + patch, but I ended up with a red error...
I swear the only thing I changed was the def names and labels? I'm not exactly sure why, but probably may have messed up somewhere. I just don't know where exactly.
Hediff & Patch test defs for reference:
Back again. Nothing has worked for me. I tried the "cataract to glaucoma" test + patch, but I ended up with a red error...
Code Select
Could not resolve cross-reference: No Verse.HediffDef named Glaucoma found to give to Verse.HediffGiver_Birthday Verse.HediffGiver_Birthday
Verse.Log:Error(String)
Verse.WantedRefForObject:TryResolve(FailMode)
Verse.DirectXmlCrossRefLoader:ResolveAllWantedCrossReferences(FailMode)
Verse.PlayDataLoader:DoPlayLoad()
Verse.PlayDataLoader:LoadAllPlayData(Boolean)
Verse.Root:<Start>m__84E()
Verse.LongEventHandler:RunEventFromAnotherThread(Action)
Verse.LongEventHandler:<UpdateCurrentAsynchronousEvent>m__84C()
I swear the only thing I changed was the def names and labels? I'm not exactly sure why, but probably may have messed up somewhere. I just don't know where exactly.

Hediff & Patch test defs for reference:
Code Select
<Defs>
<HediffDef ParentName="DiseaseBase">
<defName>Glaucoma</defName>
<label>glaucoma</label>
<stages>
<li>
<partEfficiencyOffset>-0.5</partEfficiencyOffset>
</li>
</stages>
</HediffDef>
</Defs>
Code Select
<Patch>
<Operation Class="PatchOperationAdd">
<xpath>*/HediffGiverSetDef[defName = "OrganicStandard"]/hediffGivers</xpath>
<value>
<li Class="HediffGiver_Birthday">
<hediff>Glaucoma</hediff>
<partsToAffect>
<li>LeftEye</li>
<li>RightEye</li>
</partsToAffect>
<countToAffect>2</countToAffect>
<ageFractionChanceCurve>
<points>
<li>(0.6, 0)</li>
<li>(0.75, 0.0053)</li>
<li>(0.875, 0.011045)</li>
</points>
</ageFractionChanceCurve>
</li>
</value>
</Operation>
</Patch>