When running KR&D and the latest release of ReStock/ReStock+, the KR&D interface doesn't work and new upgrades can't be applied. Replicated in a clean 1.8.1 install and got the following error in the logs:
[KRnD] Awake(): System.ArgumentException: An item with the same key has already been added. Key: Medium
at System.Collections.Generic.Dictionary2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) [0x000c1] in <ad04dee02e7e4a85a1299c7ee81c79f6>:0 at System.Collections.Generic.Dictionary2[TKey,TValue].Add (TKey key, TValue value) [0x00000] in :0
at KRnD.KRnD.getVariants (Part part) [0x00070] in :0
at KRnD.PartStats..ctor (Part part) [0x00022] in :0
at KRnD.KRnD.Awake () [0x003c0] in :0
This is followed further down the logs by a long list of errors like this, for every part:
[KRnD] updatePart(sGripStrip): System.Exception: no original-stats for part 'sGripStrip'
at KRnD.KRnD.updatePart (Part part, KRnD.KRnDUpgrade upgradesToApply) [0x00070] in :0
This is only happening with ReStock v1.1.x, using 1.0.3 there is no problem and KR&D works normally. I was able to replicate this issue with just KR&D and Restock plus their respective dependencies installed in KSP 1.8.1
Screenshots:
With ReStock 1.1.0

With ReStock 1.0.3

Also reported on the forum thread: https://forum.kerbalspaceprogram.com/index.php?/topic/191014-19x-kerbal-research-development/page/4/
When running KR&D and the latest release of ReStock/ReStock+, the KR&D interface doesn't work and new upgrades can't be applied. Replicated in a clean 1.8.1 install and got the following error in the logs:
[KRnD] Awake(): System.ArgumentException: An item with the same key has already been added. Key: Medium
at System.Collections.Generic.Dictionary
2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) [0x000c1] in <ad04dee02e7e4a85a1299c7ee81c79f6>:0 at System.Collections.Generic.Dictionary2[TKey,TValue].Add (TKey key, TValue value) [0x00000] in :0at KRnD.KRnD.getVariants (Part part) [0x00070] in :0
at KRnD.PartStats..ctor (Part part) [0x00022] in :0
at KRnD.KRnD.Awake () [0x003c0] in :0
This is followed further down the logs by a long list of errors like this, for every part:
[KRnD] updatePart(sGripStrip): System.Exception: no original-stats for part 'sGripStrip'
at KRnD.KRnD.updatePart (Part part, KRnD.KRnDUpgrade upgradesToApply) [0x00070] in :0
This is only happening with ReStock v1.1.x, using 1.0.3 there is no problem and KR&D works normally. I was able to replicate this issue with just KR&D and Restock plus their respective dependencies installed in KSP 1.8.1
Screenshots:


With ReStock 1.1.0
With ReStock 1.0.3
Also reported on the forum thread: https://forum.kerbalspaceprogram.com/index.php?/topic/191014-19x-kerbal-research-development/page/4/