Build error Failed to fetch plugin via registry

we got the following error on build

Failed UserError: Error: CordovaError: Failed to fetch plugin cordova-plugin-inappbrowser@5.0.0 via registry. Probably this is either a connection problem, or plugin spec is incorrect. Check your connection and plugin name/version/URL. This could be caused by a problem with a different plugin.

The message is right - the problem is caused by a different plugin.

You have this in your config.xml:

<plugin name="cordova-plugin-exoplayer" spec="~2.5.6" />

however, checking on npm, the latest version is 2.5.4.