I have recently had an issue while using Esri Maps for Office.
Issue: Once I have selected the rows to be geocoded, and executed the process, it starts an endless cycle of reprocessing the rows until interrupted.
Reason: A spreadsheet column(s), which contain numeric values, are formatted incorrectly. In Microsoft Excel these columns will usually have the green triangle with the Trace Error button appearing when the cell is selected.
Resolution: Convert all numeric columns to number format in the spreadsheet. For example using Microsoft Excel. Click the dropdown icon next to the Trace Error button and select ???covert to number??? or alternatively select all cells, right click selecting Format Cells and under the number tab chose Number.
I have seen this behavior before, the constant looping of the geocoding process, but it was related to special characters contained in the fields that were being geocoded. In this particular instance, there were apostrophes in one of the fields that were causing the behavior. After removing just those apostrophes, the geocoding process did not constantly loop. You may want to double-check all character and formatting aspects of the data for certain situations.
Does this behavior and resolution happen will all data you have in numeric format?
I had no 'typical' special characters in the spreadsheet. Due to the numbers being highlighted as a possible error, perhaps the software considered it as a special character? Either way fixed. Just wanted to have a resolution documented somewhere on the internet as a starting point for others.