Named Ranges are exported into NamedRanges.csv. The content of this file looks like this:
C1, C2, C3
myName1, =Sheet1!$A$1:$B$2,
myName2, =Table1[My Column Name],
myName3, =5,
...
If a header in a table contains a new line in it (by using Alt+Enter while typing in text), the CSV gets exported like this:
C1, C2, C3
myName1, =Sheet1!$A$1:$B$2,
myName2, =Table1[My Column
Name],
myName3, =5,
...
This CSV is unable to be imported.
Possible solution: sanitize the outputs by replacing new lines with \n (after replacing all occurrences of \ with \\).