Error Troubleshooting

The loading bar keeps spinning when capturing images with iPhone.

Symptom

iOS 16.4 was released on March 27th, 2023. In this version, all browsers on iOS have begun to support OffscreenCanvas. Unfortunately, Apple’s implementation of the API is still incomplete and is missing an important feature: “webgl context”. Please see the MDN docs on OffscreenCanvas for more details.

Cause

OffscreenCanvas is utilized in all versions of the Dynamic Web TWAIN Mobile Web Capture Edition. After you upgrade your iOS to v16.4, the loading bar will keep spinning when you try to capture an image. Note that the Service Edition is not affected by this issue.

Resolution

Add the following lines of code to disable the API.

if (Dynamsoft.navInfoSync.biPhone || Dynamsoft.navInfoSync.biPad) {
    window.OffscreenCanvas = null
}

Or download the patch version:

• For NPM project, please upgrade your dwt package to v17.3.4 or v18.0.2.

• For Non-NPM application, please download the new camera.js file below and replace the old file with new one under Resource/addon directory.

  • v17.3 camera.js file
  • v18.0 camera.js file

If the resolution doesn’t work for you, please contact us.