Common Installation Errors

SmartScreen blocks the installer

Windows protected your PC

Cause: the file is new or unsigned, so Microsoft Defender SmartScreen has little reputation data for it. This is common for small open-source apps.

Fix: first make sure you downloaded the file from the official source. Then click More info → Run anyway. Never do this for a file from an unofficial mirror.

Missing Visual C++ runtime

VCRUNTIME140.dll was not found MSVCP140.dll is missing

Cause: the Microsoft Visual C++ Redistributable is missing or damaged.

Fix: install the latest supported Visual C++ Redistributable for Visual Studio 2015–2022 (x64, and x86 if the app is 32-bit) from Microsoft's website, then restart.

.NET runtime required

To run this application, you must install .NET

Cause: the build you downloaded is "framework-dependent" and needs the .NET Desktop Runtime.

Fix: click the link in the message to install the runtime version it names. Or download the self-contained build or the Store version of the app, which include the runtime.

MSI error 1603

Fatal error during installation (1603)

Cause: a general Windows Installer failure. Often a previous install is half-removed, a Windows update is waiting for a restart, or the install folder is locked.

Fix: restart Windows. Remove any older version from Installed apps. Run the installer as administrator. If it still fails, create a log to find the exact step that failed:

msiexec /i naps2-setup.msi /l*v "%USERPROFILE%\Desktop\install.log"

Access denied

Error 0x80070005 Access is denied

Cause: you do not have administrator rights, or antivirus or Controlled folder access is blocking the write.

Fix: right-click → Run as administrator. Use a per-user or portable build if you are not an administrator. In Windows Security → Ransomware protection, allow the installer through Controlled folder access.

Tesseract command not found

'tesseract' is not recognized as an internal or external command

Cause: the Tesseract folder is not on your PATH.

Fix: press Win+R → sysdm.cpl → Advanced → Environment Variables → edit Path → add C:\Program Files\Tesseract-OCR. Then open a new terminal, because terminals that were already open keep the old PATH.

Tesseract language data not found

Error opening data file ... eng.traineddata Failed loading language 'eng'

Cause: the language file is missing, or TESSDATA_PREFIX points to the wrong folder.

Fix: make sure eng.traineddata is in C:\Program Files\Tesseract-OCR\tessdata. Delete or correct the TESSDATA_PREFIX variable so it points to the tessdata folder.

Store installation fails

Something unexpected happened 0x80073CF3

Cause: the Store cache is corrupted, or files from an old version of the package are conflicting.

Fix: run wsreset.exe. Uninstall any older version. Sign out of the Store and back in, then try again.

Antivirus quarantines the app

Threat detected / file removed

Cause: hotkey and screen-capture tools sometimes trigger heuristic detections because they hook the keyboard and read the screen.

Fix: check the file on the official site and against its published checksum. If it is genuine, restore it from quarantine and add an exclusion for the app's folder. Report the false positive to your antivirus vendor.