Troubleshooting

Android build fails because minSdkVersion is too low

Raise your app's minimum SDK to 26. The podofo-android artifact requires it.

The module is undefined or cannot be loaded

Check that:

• your app uses React Native's New Architecture
• react-native-nitro-modules is installed
• iOS Pods were installed after adding the package
• you are using a native development build, not Expo Go

iOS build cannot find generated Nitro headers

Run Nitrogen and then refresh Pods:

node node_modules/nitrogen/lib/index.js
cd ios
pod install

If you are in the example app, run pod install from example/ios.

pnpm nitrogen hangs or package-manager verification fails

You can call the local binary directly:

node node_modules/nitrogen/lib/index.js

This bypasses package-manager version switching and still generates nitrogen/generated.

Rendering does not include my latest edits

PdfRenderer renders from a file path. Save first:

await doc.save(path);
const bitmap = await PdfRenderer.renderPageToBitmap({ path, pageIndex: 0 });

Text appears at the wrong vertical position

PDF coordinates start at the bottom-left. React Native layout coordinates start at the top-left. Your y-axis is upside down, not your destiny.

Text extraction misses text

Possible reasons:

• the page is scanned image content with no OCR layer
• text is stored in a way the current extraction binding does not decode
• the content stream order is not visual reading order
• your regex pattern filters it out

getText() or isChecked() throws

Those methods are field-type specific. Check field.fieldType first:

if (field.fieldType === 'TextBox') {
  field.getText();
}

Signature verification returns ValidNoTrust

That is a successful byte-range integrity check, but not full certificate trust validation. You still need to validate certificate chain, trusted roots, validity dates, revocation, and your own business policy.

Signature verification returns Invalid

Invalid means the CMS signature does not cryptographically match the bytes covered by /ByteRange. It is not the same as an untrusted certificate.

Common causes:

• the PDF was modified after signing
• the verifier is pointed at a different file than the one that was signed
• your signer signed the wrong payload shape for its algorithm or hardware API
• the returned signature bytes were truncated or otherwise transformed
• RSA-2048 or larger signatures were produced with an older PoDoFo artifact that truncated decoded external signatures to 128 bytes

For RSA-2048, RSA-3072, RSA-4096, or other large external signatures, use PoDoFo 0.0.16 or newer.

Signature verification returns CouldNotVerify

Common causes:

• field has no signature value
• malformed signature contents
• missing or invalid /ByteRange
• verifying against a different file path than the signed PDF

Use field.getSignatureInfo() first and skip fields where hasSignatureValue is false.

Android rootCertificate support

rootCertificate requires PoDoFo 0.0.12 or newer. The current library version is wired for that constructor. If you manually override the Android PoDoFo artifact to an older version, Android signing with rootCertificate can throw.

Large PDFs use too much memory

PoDoFo loads the document structure and lazily loads streams, but page copying is not a true streaming split operation. For very large PDFs:

• process small page ranges
• save each output document separately
• release output documents between batches
• consider reopening the source for each batch if memory is more important than speed
• avoid returning huge buffers to JS

The safe rule: keep big binary work native and file-based.

painter.finishDrawing() was forgotten

Call it once when done drawing. If content is missing or the output is malformed after drawing, this is one of the first things to check.

Still stuck?

Open an issue on GitHub with:

• React Native version
• platform and OS version
• package version
• whether New Architecture is enabled
• native build log
• minimal code snippet
• a sample PDF if the issue depends on a specific file