Error during upgrades

Failed to call hook 'UpCommand' on plugin 'StructureUpgrade v0.6.3' (IndexOutOfRangeException: Index was outside the bounds of the array.)
  at Oxide.Plugins.StructureUpgrade.GetBlocksAndCost (BuildingManager+Building building, System.Int32 grade, System.Boolean isDowngradeJob) [0x00074] in <fa9b02caf6c643cd9762e06c2b1625f9>:0 
  at Oxide.Plugins.StructureUpgrade.Upgrade (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args, Oxide.Plugins.StructureUpgrade+PaymentMethod paymentMethod) [0x0015f] in <fa9b02caf6c643cd9762e06c2b1625f9>:0 
  at Oxide.Plugins.StructureUpgrade.UpCommand (Oxide.Core.Libraries.Covalence.IPlayer player, System.String command, System.String[] args) [0x00000] in <fa9b02caf6c643cd9762e06c2b1625f9>:0 
  at Oxide.Plugins.StructureUpgrade.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x000b0] in <fa9b02caf6c643cd9762e06c2b1625f9>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <e23ba2c0f246426296d81c842cbda3af>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <46ff2b534abb4b35952608167523b7ec>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <46ff2b534abb4b35952608167523b7ec>:0 

Unload the plugin, delete the datafile, load the plugin. Working on a data file redesign that should hopefully resolve this issue.