Lost connection to device

I have developed an app that uses a InAppWebview page. I have added in flutter_downloader and set it up to work when a downloadable link is clicked, but after it finishes the download the app crashes, after this error.

I/flutter (22213): Fatal: could not find callback
D/HostConnection(22213): HostConnection::get() New Host Connection established 0xe85a67c0, tid 23207
D/HostConnection(22213): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_YUV420_888_to_NV21 ANDROID_EMU_YUV_Cache ANDROID_EMU_async_unmap_buffer GL_OES_EGL_image_external_essl3 GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_async_frame_commands ANDROID_EMU_gles_max_version_3_0
Lost connection to device.

I have no idea if the callback error is a warning or the cause of the problem, or what it even means. Can anyone point me in the right direction thanks.