SignalTap: error: type of identifier does not agree . . . .

I added SignalTap to my design and I get the following error when I compile: 10476 VHDL error at sld_signaltap.vhd(82): type of identifier "false" does not agree with its usage as "natural" type.

The IP generator created the code that has errors.

I've been using SignalTap for 10 years and I've never seen this error before.

The target device is a MAX 5.