Home → Troubleshooting → @RISK for Excel: Simulation → "An exception of unknown type has occurred."
Applies to: @RISK for Excel
When I try to run a simulation, I get the message
An exception of unknown type has occurred.
What is wrong, and how do I fix it?
There are several possible problems, so let's start with the most likely ones before we look at more complicated possibilities.
First, does this happen with only one particular workbook? For example, can you simulate one of our examples successfully? (Click Help » Example Spreadsheets.) If it's only a particular workbook, please email it to us at support@palisade.com and we'll have a look.
On the other hand, if you also get the error with other workbooks then it is likely to be a configuration problem.
You should not manually add any of our libraries or toolbars to Excel. If you have done that, please remove them, close Excel, and then run @RISK in the recommended way: click the Windows Start button, then Programs or All Programs, then Palisade DecisionTools, then @RISK for Excel.
You may have some other add-ins that are incompatible, or you may have macro files or template files that are incompatible. Please see the appropriate article for help in diagnosing startup conflicts:
Find and Fix Startup Conflicts (Excel 2007–2016)
Find and Fix Startup Conflicts (Excel 2003 and Earlier)
Last edited: 2015-01-05