I think in early Forge 1.14, the provider was originally invalid, which is probably the reason for your code, but that is fixed for some time now (https://github.com/MinecraftForge/MinecraftForge/pull/5728). At least I did not have any issues with this since then.
If you still want to keep that code, please make sure to set valid to the original value instead of false.
AoV uses reflection to make sure the player's capability provider is valid upon PlayerClone. After copying its own capabilities, it invalidates the provider (regardless of its previous state): https://github.com/Tamaized/AoV/blob/ae514b39463d4b8a471c10c5bdd86df2e47af3dc/src/main/java/tamaized/aov/common/capabilities/CapabilityList.java#L198
However, the provider is originally
valid, so the code is not only unnecessary, but also breaks other mods like Vampirism: https://github.com/TeamLapen/Vampirism/issues/577I think in early Forge 1.14, the provider was originally invalid, which is probably the reason for your code, but that is fixed for some time now (https://github.com/MinecraftForge/MinecraftForge/pull/5728). At least I did not have any issues with this since then.
If you still want to keep that code, please make sure to set
validto the original value instead of false.