One possibility is that the third-party software was compiled for the wrong player, i.e., a Mark1 rather than a Mark2, or vice-versa. Always make sure it's the right version before sending it to the player.

However, even in that situation, applying a standard ".upgrade" file should still fix the problem (assuming you had the correct Mk1/Mk2 version of the upgrade file). If it doesn't (as you suggested), then I need to add stronger warnings to my kernel-uploading FAQ.

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Tony Fabris