Attempting to sync over an existing `PackageLink` causes Rojo plugin to error out about rojo

[Helloburp]

Hiya, this still appears to be happening for me on 7.4.1.

I encountered this in one of my own projects, then found this issue and attempted to build the .zip and got what seems to be the same result:

-- Promise.Error(ExecutionError) --

The Promise at:

user_RojoManagedPlugin.rbxm.Rojo.Plugin.ServeSession:142 function start
user_RojoManagedPlugin.rbxm.Rojo.Plugin.App:560 function startSession
user_RojoManagedPlugin.rbxm.Rojo.Plugin.App:641 function onConnect
user_RojoManagedPlugin.rbxm.Rojo.Packages.Roact.SingleEventManager:80

...Rejected because it was chained to the following Promise, which encountered an error:

user_RojoManagedPlugin.rbxm.Rojo.Packages.Log:57: Could not compute a diff to catch up to the Rojo server: {
    ["details"] = {
        ["propertyName"] = "SerializedDefaultAttributes",
        ["className"] = "PackageLink",
    },
    ["kind"] = {},
}
user_RojoManagedPlugin.rbxm.Rojo.Packages.Log:57 function error
user_RojoManagedPlugin.rbxm.Rojo.Plugin.ServeSession:229
user_RojoManagedPlugin.rbxm.Rojo.Packages.Promise:172 function runExecutor
user_RojoManagedPlugin.rbxm.Rojo.Packages.Promise:181

Promise created at:

user_RojoManagedPlugin.rbxm.Rojo.Plugin.ServeSession:212 function __initialSync
user_RojoManagedPlugin.rbxm.Rojo.Plugin.ServeSession:145
user_RojoManagedPlugin.rbxm.Rojo.Packages.Promise:172 function runExecutor
user_RojoManagedPlugin.rbxm.Rojo.Packages.Promise:181