Can't "increase options" on IVR

Running FreePBX 2.3.1, IVR module is which is reported as “Enabled and up to date.” When I click on “Increase Options” I get nothing but a blank white screen, and the options are not increased. When I try to change an existing option and click on “Save”, I also get a blank white screen but the change seems to “take” nonetheless. If I click on “Add IVR” it appears to allow that (and gives me three new options) but if I then try to “Increase Options” on the new IVR it gives me the blank white screen. I’m wondering if something got messed up in the last IVR module upgrade (I tend to install offered module upgrades, perhaps I shouldn’t) or if I’m having some other weird problem. Is anyone else experiencing this same issue (particularly anyone still running a FreePBX 2.3.x version)?