The problem's basically all in the title, but it's a really awful situation. I've tried to see if anyone else has had the same issue, but could not find anything.
If it helps, this is what I get in the "Plugin Error" window:
File: C:\Program Files\Paint.NET\Effects\Outline Object.dll
Effect Name: pyrochild.effects.outlineobject.OutlineObject
Full error message: PaintDotNet.WorkerThreadException: Worker thread threw an exception ---> System.TypeLoadException: Could not load type 'PaintDotNet.PdnInfo' from assembly 'PaintDotNet.Resources, Version=4.0.5288.36565, Culture=neutral, PublicKeyToken=null'.
at pyrochild.effects.outlineobject.OutlineObject.OnSetRenderInfo(PropertyBasedEffectConfigToken newToken, RenderArgs dstArgs, RenderArgs srcArgs)
at PaintDotNet.Effects.Effect`1.OnSetRenderInfo(EffectConfigToken parameters, RenderArgs dstArgs, RenderArgs srcArgs) in D:\src\pdn\paintdotnet\src\Effects\Effect`1.cs:line 67
at PaintDotNet.Effects.BackgroundEffectRenderer.ThreadFunction() in D:\src\pdn\paintdotnet\src\PaintDotNet\Effects\BackgroundEffectRenderer.cs:line 220
--- End of inner exception stack trace ---
at PaintDotNet.Effects.BackgroundEffectRenderer.DrainExceptions() in D:\src\pdn\paintdotnet\src\PaintDotNet\Effects\BackgroundEffectRenderer.cs:line 431
at PaintDotNet.Effects.BackgroundEffectRenderer.Abort() in D:\src\pdn\paintdotnet\src\PaintDotNet\Effects\BackgroundEffectRenderer.cs:line 387
at PaintDotNet.Effects.BackgroundEffectRenderer.Start() in D:\src\pdn\paintdotnet\src\PaintDotNet\Effects\BackgroundEffectRenderer.cs:line 333
at PaintDotNet.Menus.EffectMenuBase.<>c__DisplayClass31.<>c__DisplayClass35.<RunEffectImpl>b__25() in D:\src\pdn\paintdotnet\src\PaintDotNet\Menus\EffectMenuBase.cs:line 1003