I had created ArcGIS Pro project with one Map this map was imported from ArcMap MXD, The map contains multiple layer already symbolized using unique value renderer single or multiple fields, In both cases when I try to add new value to symbol classes using the following steps:
- Right click layer
- Select symbology to open symbology pan
- The Symbology is already using "Unique value" method.
- Then click "add unlisted values" button.
- Then from options click "Add new value"
but rather than add new value and enter value and label it return the following message :
"Requested operation could not be completed"
Note : when I tried in a new Map with layer added and symbolized in ArcGIS pro I can add unlisted value that has no matching data record using "add new value" option.
So what could be the issue in my case, any suggestion ?
