"Unexpected error" with decision tables blocking the web page

I create a decision table.
The table validates.
I save the table and close the editor.
The project builds.
I open the editor again.
An error pops out with the message "Unespected error". Clicking on either the Ignore button or the "x" icon does not make it go away because it seems to be generated in an infinite loop practically locking the web page. I have to close the web page entirely to get out of it.

This issue is caused apparently by comparing two strings with the "<" or ">=" operators.
Each row of the table has in the "when" section an expression such as

AccountHolder( BALANCE < "2500")

If I change the type of the attribute BALANCE from String to Double the expression above becomes

AccountHolder( BALANCE < 2500.0 )

and the issue no longer occurs.

The original syntax passes validation and the project was building. The same syntax does not cause any problem in the Guided Rule Editor. It seems that the Guided Decision Table Editor can't handle string comparisons using "<" and ">=".

If "<" and ">=" should be used only with numeric variables the rule should not validate nor the project should build but it does. If it is ok to compare strings with "<" and ">=" the editor should not get all confused by it.