There have been significant changes and updates in the miRNA naming conventions over the past decade. As a result, many miRNA annotations and IDs are not valid any more. The miRNet functional annotations and associations are based on miRNA IDs and Accessions of the current miRBase (version 22). We strongly recommend you to double check and update your miRNA IDs against the current miRBase if there are no hits found for you input.
If you are doing miRNA expression analysis, you can analyze the data first to identify significant miRNAs and then manually updates the IDs for those miRNAs. The updated miRNAs can be copy-and-paste as a list for network analysis and interpretation using miRNet.