[Target] PPDInstaller
[x86 or x64] x64
[Windows OS] Windows 10
[Content] Instead of installing PPD the installer just returns "Fatal Error" and stops. (fix at the end of this thread; scroll down :)
[error.log exists] Yes
[What you did before error] Nothing special; just downloaded, extracted and ran the installer.
[PPD.ini] (i assume you only get this after a successful install? I couldn't find it..)
------------------------------------------------------------------
17/07/2021 13:01:37
FullName:PPDInstaller, Version=1.0.0.2, Culture=neutral, PublicKeyToken=null
Assembly:D:\Downloads\PPDInstaller(x64)\PPDInstaller.exe
Name:PPDInstaller.exe
FileVersion:1.0.0.1
ProductVersion:1.0.0.1
RefAssembly:mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
RefAssembly:System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
RefAssembly:System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
RefAssembly:PPDConfiguration, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
RefAssembly:ErrorHandle, Version=1.1.2.0, Culture=neutral, PublicKeyToken=null
RefAssembly:System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
RefAssembly:Interop.IWshRuntimeLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
RefAssembly:ICSharpCode.SharpZipLib, Version=0.86.0.518, Culture=neutral, PublicKeyToken=1b03e6acf1164f73
System.Collections.ListDictionaryInternal

1 is not a supported code page.
Parameter name: codepage
mscorlib
at System.Text.Encoding.GetEncoding(Int32 codepage)
at ICSharpCode.SharpZipLib.Zip.ZipFile.ReadEntries()
at ICSharpCode.SharpZipLib.Zip.ZipFile..ctor(Stream stream)
at ICSharpCode.SharpZipLib.Zip.FastZip.ExtractZip(Stream inputStream, String targetDirectory, Overwrite overwrite, ConfirmOverwriteDelegate confirmDelegate, String fileFilter, String directoryFilter, Boolean restoreDateTime, Boolean isStreamOwner)
at PPDInstaller.Utility.Unzip(String path, String unzippath)
at PPDInstaller.ExtractDialog.<ExtractDialog_Load>b__9_0()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
System.Text.Encoding GetEncoding(Int32)
------------------------------------------------------------------

To fix this you need to
1. open the (Windows) settings
2. search for "Set regional format"*
3. change it to "English (United Kingdom)"**

Then run the installer again and it should work. I hope this helps at least one person. :)

*alternatively navigate to "Time & Language" > "Region"
** make sure you change only the Regional format and not the Region.

Thank you so much for posting the way to fix it!!
I just stumbled across this problem for the first time while trying to reinstall PPD, and your instructions worked perfectly. Thanks! :)