INNO TROUBLESHOOT - Questions Here

[Masquerade]

^^
I don't see why you wouldn't be able to put an Exec2 leading to a batch file before ISDone (or whatever implementation you use to bridge Inno Setup and FreeArc) starts.

A suggestion,

Paste this into a batch file and save it as disable_path_limit.bat:

REG ADD "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem" /v "LongPathsEnabled" /t REG_DWORD /d 1 /f

Add this section to the [Files] section in your script:

Source: disable_path_limit.bat;  DestDir: {tmp}; Flags: dontcopy

Then somewhere in your script (e.g. just after arc.ini is extracted for example), add this code section:

ExtractTemporaryFile('disable_path_limit.bat');
Exec2(ExpandConstant('{tmp}\disable_path_limit.bat'),'',false);
DeleteFile(ExpandConstant('{tmp}\disable_path_limit.bat'));

Providing that you put that section of code just after arc.ini is extracted (if you are unsure where this is, CTRL+F for "ExtractTemporaryFile('arc.ini');" to find it easy) it will run and the reg will get updated before the archives are unpacked.

Note that this batch file requires admin permissions so providing the installer is running in an elevated state, the script should face no issues.