The typically appears in situations where Windows, Linux, and macOS users attempt to stream content from Hulu. Users that are seeing this problem are reporting that this problem occurs with every piece of Hulu content that they attempt to stream.
As it turns out, there are several different causes that might cause this problem depending on the platform where you’re seeing the DRMCDM78 error code:
Hulu Server issue – First things first, you should investigate and see whether this issue is not somehow caused by a server issue that is beyond your control. If that’s the case, there is no fix for the problem other than waiting for the developers to fix the issue on their side.
Outdated browser repository – As it turns out, this problem can also occur in instances where your default browser has just changed their repository and the old version is no longer capable of supporting streaming protocols. In this case, all you need to do is update your browser to the latest version available.
Corrupted cached data – In some cases, you might see this error due to some type of corrupted temporary files that your browser cache is currently holding. In this case, you should be able to resolve the problem by
TCP / IP Issue – Under certain circumstances, this problem can also result from a TCP or IP inconsistency. If this scenario is applicable, you should be able to fix the problem either by rebooting your router or performing a reset procedure.