The following works in v11.2-12.0:

```
ts1 = TimeSeries({{0, 0}, {1, 1}, {2, 0}, {3, 1}});
ts2 = TimeSeries({{0, 1}, {1, 0}, {2, 1}, {3, 0}});
Covariance(ts1, ts2)
(* -1/3 *)
```

fails in version 10.0-10.3 with the message:

Covariance :: vctmat: The arguments for covariance are not a pair of vectors or a pair of matrices of equal length.

The same problem occurs for `TemporalData`

, however `Variance`

and `Mean`

both work in all these versions:

```
Variance(ts1)
(* 1/3 *)
Mean(ts1)
(* 1/2 *)
```

Error? Bypass?