PKHeX Plugins no longer working

[Lafell]

I've been using PKHeX for a quite a while now, but about last week I discovered certain plugins you can use to help with certain things such as finding Feebas in older gens. Prior to this update (April 1st), I was able to run the plugins just fine, but now, I receive an error whenever I try to run the plugin under tools on the app.

Exception Details:
System.MissingMethodException: Method not found: 'Int32 PKHeX.Core.SAV3.GetBlockOffset(Int32)'.
   at FeebasLocatorPlugin.FeebasLocatorForm..ctor(SaveFile sav)
   at FeebasLocatorPlugin.FeebasLocator.OpenFeebasLocatorForm(Object sender, EventArgs e)
   at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e)
   at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e)
   at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e)
   at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e)
   at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea)
   at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ToolStrip.WndProc(Message& m)
   at System.Windows.Forms.ToolStripDropDown.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Loaded Assemblies:
--------------------
mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\mscorlib.dll

PKHeX, Version=21.4.1.0, Culture=neutral, PublicKeyToken=null
C:\Users\zachc\Downloads\PKHeX\PKHeX.exe

System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll

System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Windows.Forms\v4.0_4.0.0.0__b77a5c561934e089\System.Windows.Forms.dll

System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Drawing\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Drawing.dll

System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll

System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Core\v4.0_4.0.0.0__b77a5c561934e089\System.Core.dll

System.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.Xml\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.dll

PKHeX.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

PKHeX.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

PKHeX.Drawing, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null

FeebasLocatorPlugin, Version=1.2.0.0, Culture=neutral, PublicKeyToken=null
C:\Users\zachc\Downloads\PKHeX\plugins\FeebasLocator.dll

OptaneShellExt, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b2b395177cd09cef
C:\Program Files\Intel\OptaneShellExtensions\OptaneShellExt.dll

SharpShell, Version=2.2.0.0, Culture=neutral, PublicKeyToken=f14dc899472fe6fb
C:\Program Files\Intel\OptaneShellExtensions\SharpShell.dll

log4net, Version=1.2.15.0, Culture=neutral, PublicKeyToken=669e0ddf0bb1aa2a
C:\Program Files\Intel\OptaneShellExtensions\log4net.dll

PinningServiceApi, Version=1.0.0.0, Culture=neutral, PublicKeyToken=d2c7ef10062b7593
C:\Program Files\Intel\OptaneShellExtensions\PinningServiceApi.dll

System.ComponentModel.Composition, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
C:\Windows\Microsoft.Net\assembly\GAC_MSIL\System.ComponentModel.Composition\v4.0_4.0.0.0__b77a5c561934e089\System.ComponentModel.Composition.dll

--------------------
User Message:
An unhandled exception has occurred.
You can continue running PKHeX, but please report this error.

 

I've looked at other forum posts about questions liked this but I haven't really been able to find a solution that works for me. I've seen some saying that the plugin is out of date, which makes sense, but I don't understand how it would work with the previous update from January if the plugin hasn't been updated since about a year ago?
 

[Kaphotics]

Read the PKHeX changelog.

Plugins that used the old Gen3 save file methods will need to be updated.

[Lafell]

Sorry, I skimmed through the changelog way too fast. I'll just use the older version until then whenever I need to use those plugins. Thanks for the quick reply, I really appreciate it.