When I'm adding a simple custom expression for summarization I get a " Something's gone wrong We've run into an error. You can try refreshing the page, or just go back."

`Disctinct([Learner ID])`

works whereas `Distinct(case([Active],[Learner ID]))`

breaks the moment the expression field loses focus.

Inspecting the developer console yields the below:

```
segment with ID does not exist: undefined react-dom.production.min.js:209:194
Error:
Object { componentStack: "\n in o\n in ExplicitSize[o]\n in div\n in div\n in Styled(div)\n in div\n in Styled(div)\n in cs\n in DK\n in BK\n in div\n in u\n in span\n in l\n in Triggerable[l]\n in div\n in NotebookCell\n in fW\n in FK\n in div\n in Styled(div)\n in div\n in Styled(div)\n in oY\n in div\n in Styled(div)\n in div\n in Styled(div)\n in div\n in Styled(div)\n in div\n in u\n in lX\n in div\n in Styled(div)\n in bX\n in div\n in Styled(div)\n in Unknown\n in l\n in Connect(l)\n in EntityType\n in Connect(EntityType)\n in Unknown\n in div\n in Styled(div)\n in eae\n in div\n in Styled(div)\n in div\n in Styled(div)\n in div\n in o\n in ExplicitSize[o]\n in Unknown\n in Unknown\n in Title[]\n in Title[Title[]]\n in Favicon\n in Connect(Favicon)\n in o\n in Connect(o)\n in a\n in EntityType\n in Connect(EntityType)\n in Connect(EntityType)\n in Connect(Favicon)\n in l\n in o\n in Connect(o)\n in a\n in EntityType\n in Connect(EntityType)\n in Connect(EntityType)\n in Connect(Favicon)\n in Unknown\n in UserIsAuthenticated(Component)\n in Connect(UserIsAuthenticated(Component))\n in MetabaseIsSetup(Connect(UserIsAuthenticated(Component)))\n in Connect(MetabaseIsSetup(Connect(UserIsAuthenticated(Component))))\n in main\n in Styled(main)\n in div\n in Styled(div)\n in div\n in Styled(div)\n in o\n in withRouter(o)\n in s\n in Unknown\n in Connect(Component)\n in Title[Connect(Component)]\n in RouterContext\n in Router\n in p\n in @mantine/core/MantineProvider\n in ForwardRef\n in DragDropContextProvider\n in I" }
app.ts:22:10
Warning: can't clean query without metadata!
```

Last step before crash:

After crash:

b