The below code executes.  If I uncomment the Plot, it runs for a while and outputs nothing, not even the Mean and Variance.



----------
```
new2 = TransformedDistribution[(x + y + z)/3, {x, y,z} \[Distributed] LogMultinormalDistribution[{0,1,0},{{1,0,0},{0,1,0},{0,0,1}}]];

lmdpdf = PDF[new2,x];

(* Plot[%, {x, 1, 8}, Filling -> Axis,PlotRange -> Automatic]  *)

Mean[new2]
Variance[new2]
```
========

Meanwhile, the below works fine.

--------
```
new2a = TransformedDistribution[(x + y),
 {x\[Distributed] NormalDistribution[],
y \[Distributed] NormalDistribution[]} 
];

PDF[new2a, x];

Plot[%, {x, -6, 8}, Filling -> Axis,PlotRange -> Automatic]

Mean[new2a]
Variance[new2a]
```

===

ADDED in response to comment.  The below runs fine, including plot. I *think* it is the same as a 2 variable version of my non-plotting Transform. 
 
===

```
new2a = TransformedDistribution[(x + y),
 {x\[Distributed] LogNormalDistribution[0,1],
y \[Distributed] LogNormalDistribution[0,1]
} 
]
```
Added more: tried exactly two variable version, and it fails to plot.  Sans Plot function, it returns the same Mean and Variance though, so I am even more confused.  This is apparently not a Plot issue, but a closed/open form issue combined with a built-in-symbols question...

```
new2 = TransformedDistribution[(x + y + z), {x,y,z} \[Distributed] LogMultinormalDistribution[{0,1,0},{{1,0,0},{0,1,0},{0,0,1}}]];
```
dividing by 2 (see below) also causes code to fail, which doesn't feel like it is a closed/open form issue, but I have no idea what MMA is doing under the covers ...

```
new2a = TransformedDistribution[(x + y)/2,
 {x\[Distributed] LogNormalDistribution[0,1],
y \[Distributed] LogNormalDistribution[0,1]
} 
]
```

[![Function without closed form successfully plots][1]][1]


  [1]: https://i.sstatic.net/E9j1beZP.png