Inno setup ошибка

Although I really like InnoSetup, I have been suffering with this erroneous message for some time, but my frustration has reached new heights. There are numerous posts complaining about this problem, which is most certainly an InnoSetup bug, but no useful work-arounds that I can find.

I have a very simple (signed) setup that merely copies some files and creates a shortcut. It does not even include an executable. When I try to compile the setup, I am getting this «the process cannot access the file because it is being used by another process» message — repeatedly (normally I always get the setup to compile within 3 tries), but now it seems futile after many. many tries. The file that is «in-use» is not clear from the InnoSetup output or error dialog. There are most definitely no competing processes running. (I have rebooted the machine and still get this message).

Any ideas on how to resolve this are much appreciated.

Here is the complete setup code — it is signed, but that is not a problem with other setups I have created with the same signature.

#define MyAppName "Easy-IAP for IronKey"
#define MyAppVersion "4.0"
#define MyAppPublisher "Command Post Solutions"
#define MyAppURL "http://www.commandpostsolutions.com/"

[Setup]
; NOTE: The value of AppId uniquely identifies this application.
; Do not use the same AppId value in installers for other applications.
; (To generate a new GUID, click Tools | Generate GUID inside the IDE.)
AppId={{51668D56-27F6-4C83-87F2-677328EFE808}
AppName={#MyAppName}
AppVersion={#MyAppVersion}
;AppVerName={#MyAppName} {#MyAppVersion}
AppPublisher={#MyAppPublisher}
AppPublisherURL={#MyAppURL}
AppSupportURL={#MyAppURL}
AppUpdatesURL={#MyAppURL}
DefaultDirName="\EZ-IAP"
DefaultGroupName={#MyAppName}
DisableProgramGroupPage=yes
OutputBaseFilename=IronKeySetup
SetupIconFile=C:\Users\ron\Dropbox\EZIAP\eziap.ico
Compression=lzma
SolidCompression=yes
SignedUninstaller=yes
SignTool=Standard /d $qEasy-IAP Installer$q $f                                                                   

[Languages]
Name: "english"; MessagesFile: "compiler:Default.isl"

[Files]
Source: "C:\Users\ron\Dropbox\Easy-IAP for IronKey\AccessDatabaseEngine.exe"; DestDir: "{app}"; Flags: onlyifdoesntexist
Source: "C:\Users\ron\Dropbox\Easy-IAP for IronKey\dotNetFx40_Full_x86_x64.exe"; DestDir: "{app}"; Flags: onlyifdoesntexist
Source: "C:\Users\ron\Dropbox\Easy-IAP for IronKey\Easy-IAP for IronKey\bin\Release\Easy-IAP for IronKey.exe"; DestDir: "{app}";
; NOTE: Don't use "Flags: ignoreversion" on any shared system les
[ICONS]
Name: "{drive:{app}}\Easy-IAP"; Filename: "{app}\Easy-IAP for IronKey.exe"; 

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