You have symbol level drawing properties defined for a map layer from an older (version 8.3 or earlier) map document. You need to upgrade the symbol level drawing properties before you can import the map document into ArcGIS Pro.
Solution
Upgrade your symbol-level drawing properties to the current version of ArcMap. Follow these steps:
- Right-click the data frame in the table of contents and click Advanced Drawing Options.
- Click the Symbol Drawing tab.
- Click Upgrade.
- Click OK.
- Save your map document.
- Reimport the map document.
More information
Symbol level drawing allows you to achieve special cartographic effects by giving you control over the drawing order of feature symbology. You specify the order that symbols and symbol layers for multilayer symbols are drawn on your map—overriding the default ArcMap drawing sequence. With symbol level drawing, the drawing order is based on each feature's symbol and the position of that symbol in the symbol level drawing order. Symbol level drawing parameters can be set individually for each feature layer or group layer. See What is symbol level drawing? for more information.
Your map document file was most likely created in ArcMap 8.3 with Advanced Drawing Options enabled. You will need to upgrade your document to use ArcGIS symbol level drawing before you can import your map document into ArcGIS Pro.
At ArcMap 8.3, the symbol level drawing properties were stored with the Advanced Drawing Options for the data frame. Version 8.x style symbol level drawing allowed any symbol level in the entire data frame to be intermixed in drawing order. To preserve the appearance of your map, you may need to combine multiple layers in a group layer and enable symbol level drawing for that group layer. This will allow you to mix drawing order of symbol levels from multiple layers.