Updating an old mac
What I found to be the problem was the formula and the fact that I surrounded numbers with quotes.
If such a device is malfunctioning and the manufacturer does not offer special drivers, examine the USB cable and connections, or look in the device's or the operating system's control panels for issues with the device or with the Universal Serial Bus controllers. Windows users can try updating their drivers via Device Manager in the first instance, before looking for drivers on the internet.In Settings I had to change Automatic Update command to Full Calculate and then back again.Once the original setting had been restored, the add-in ran as normal."Icons" views have a direct link to Device Manager, as does "Classic View" on Windows Vista only.Windows XP and earlier: Click , click on the Hardware tab, then on the "Device Manager" button on the Device Manager panel.To do this, you can use Device Manager on Windows, System Profiler on a Mac or the /lspci or /lsusb commands on Linux.
Device Manager can also try and update the drivers for you itself, and Windows users are strongly recommended to try this update facility as a first step - see Extra help for Windows users below.
Drivers are the piece of software that tells your computer how to talk to the specific hardware you have installed or connected to your computer.
The drivers must be specific to the particular model of your computer or sound device, and are usually produced by the sound device or motherboard manufacturer.
I opened this spreadsheet, checked that this was still working and autoupdating with current installation of MS Excel and any new automatic office updates (which it did work with), and then just reopened the original spreadsheet. In my instance I was using a particular add-in called PI Datalink.
Somehow PI's Calculate method was no longer running during the normal workbook recalculate.
I also have had this problem with a very large spreadsheet that just stopped updating itself over the weekend, but having checked the above solutions, setting were already set to automatic, and sheet is too big to rebuild, so I was at a loss.