When a field name in a feature layer contains underscores and alphanumerical values (e.g. '_x9000x_x_i'), running the Table To Excel geoprocessing tool to export to the .xlsx format from ArcGIS Pro causes the field name to have special characters instead of its original name.

Workaround

There are two possible workarounds:

Workaround 1 - Specify the output file as .xls

1. Add a field with a name containing underscores and alphanumerical values (e.g. '_x9000x_x_i') to a table or feature class in ArcGIS Pro; Data Type can be Long.
2. Run the Table To Excel geoprocessing tool and specify the output file as .xls.
3. View the output file in Excel. Special characters are not present in the field name.

Workaround 2 - Specify _the output file_ as .xlsx

1. Add a field with a name containing underscores and alphanumerical values (e.g. '_x9000x_x_i') to a table or feature class in ArcGIS Pro; Data Type can be Long.

2. Run the Table To Excel geoprocessing tool and specify the output file as .xlsx.

3. Check 'Use field alias as column header'.

4. View the output file in Excel. Special characters are not present in the field name.

Steps to Reproduce