10058: The network dataset has not been dissolved
The network dataset has not been dissolved. Dissolving the network dataset may reduce the time it takes to solve network analyses, draw their results, and generate driving directions. Dissolving a larger network dataset (for example, a statewide or nationwide network) results in significant time savings, whereas dissolving a small network, such as a citywide network, has little to no benefit.
Solution
Use the Dissolve Network geoprocessing tool to dissolve the network dataset. Make sure that you build the output network dataset after the tool runs successfully.
Do nothing. You can choose to accept the drawbacks and ignore the warning.
More information
A dissolved network minimizes the number of line features required to correctly model the input network dataset. The leaner output network can be queried more efficiently for analysis and visualization.