Missing metadata entities could result in bugs at runtime. For example, if a native class has been accidentally filtered out, its constructor function will be`undefined` and this will lead to an exception when its attempted to be called. Figuring out what is the reason for something being`undefined` could be quite difficult because the reasons can vary. To check whether metadata filtering is to blame or not you should examine metadata generator's verbose logs after a successful build:

- On iOS they are located in`platforms/ios/build/<configuration>-<platform>/metadata-generation-stderr-<arch>.txt` (e.g.`platforms/ios/build/Debug-iphonesimulator/metadata-generation-stderr-x86_64.txt`);

- On Android they are located in`platforms/android/build-tools/buildMetadata.log`

- On Android they are located in`platforms/android/build-tools/mdg-java-out.txt`

For each global symbol that is discovered by the generator, there should be a line providing information whether it was included in the metadata or not, and which rules or what exception caused this. Examples: