Error (13657): VHDL expression error at <file name>.vhd: expression has 1 element, but must have 2 elements

Description

Due to a problem in the Quartus® Prime Pro Edition software version 17.1 and earlier, you may see this error when using a reduction operator (for example, OR_REDUCE) on a single-element array.

In VHDL 2008, this should return the value of the element.

Resolution

To work around this problem, do not use reduction operators on single-element arrays.

This problem will be fixed in a future release of the Quartus® Prime Pro Edition software.