What steps will reproduce the problem?
1. typing /mrplow ignore add (link to hearthstone)
2.
3.

What is the expected output? What do you see instead?

I expect it to accept the request.  Upon pressing return at the command line, this error is thrown and the cursor returns to the command line without actually processing it.

The following LUA error:

Message: Interface\AddOns\MrPlow\PlowEngine.lua:948 table index is nil
Time: 12/21/09 07:28:53
Count: 1
Stack: Interface\AddOns\MrPlow\PlowEngine.lua:948 in function `AddWatchList'
Interface\AddOns\MrPlow\MrPlow.lua:159 in function `?'
...ddOns\AutoBar\libs\AceConsole-3.0\AceConsole-3.0.lua:94 in function `value'
Interface\FrameXML\ChatFrame.lua:3565 in function `ChatEdit_ParseText'
Interface\FrameXML\ChatFrame.lua:3213 in function `ChatEdit_SendText'
Interface\FrameXML\ChatFrame.lua:3237 in function `ChatEdit_OnEnterPressed'
[string "*:OnEnterPressed"]:1: in function <[string "*:OnEnterPressed"]:1>

Locals: self = PlowEngine {
 0 = <userdata>
 RunJob = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:183
 CheckMove = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:787
 ShowWatchList = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:957
 StopEverything = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:936
 MoveSlot = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:781
 ReverseProcessBags = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:892
 Consolidate = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:251
 AddWatchList = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:944
 ProcessBags = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:865
 Defragment = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:394
 ClearWatchList = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:953
 MassSort = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:707
 Enable = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:30
 RunGuildBankJob = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:232
 NextSlot = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:921
 OnUpdate = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:835
 Restack = <function> defined @Interface\AddOns\MrPlow\PlowEngine.lua:289
}
ItemList = "ignore add  [Hearthstone]"
link = nil
(for generator) = <function> defined =[C]:-1
(for state) = nil
(for control) = "Hearthstone]|"
link = "Hearthstone]|"
item = nil
(*temporary) = <table> {
 6948 = true
}
(*temporary) = nil
(*temporary) = "Hearthstone]|"
(*temporary) = "item:(%d+):"
(*temporary) = nil
(*temporary) = "table index is nil"
watch = <table> {
 6948 = true
}

What version of the product are you using?

Version:  10.1
X-Curse-Packaged-Version: v10.2.6.3-Beta

Do you have an error log of what happened?

Posted above.

If MrPlow is looping endlessly over a few items follow the instructions below:

1. Take note of which items are being swapped. Be aware, that it will almost always involve at least 3 items at most times.
2. use  /mp add [Blocky Item of Block][Womble cabbage of Frog][Fried Green Tomatoes] (use shift-click on the items)
3. run /mp sort and copy/paste the resultant output to the ticket (after hitting /mp stop after it loops)
4. note /mp watching and /mp clear will show what's being monitored and clear the list respectively.

Please provide any additional information below.