Ability to parse multiline logs

[Vit-P]

For Custom reciever, With Custom Columniser I was not been able to configure app to parse logs with massages that span across several lines
E.g.:

2019-01-01 23:31:42,052~ERROR~83~Class.One.Two.Three~Method~Message blah blah blah
Stack1
   at Stack.Stack...
some oher stuff
2019-01-01 23:31:44,999~INFO~83~Class.One.Two.Three~Method~Message blah blah 123

It does work with following regex in the test window
\d{4}-\d{2}-\d{2} \d{2}\:\d{2}\:\d{2}\,\d+?\~\w+?\~\d+?\~.+?\~.+?\~((?:.|\n)+?)(?=(?:\d{4}-\d{2}-\d{2} \d{2}\:\d{2}\:\d{2}\,\d+?\~)|\n$)
But when I try to open actual file, it does not parse it, and it appears to be empty