Message type: E = Error
Message class:  CNV_IUUC_ODQ - Error messages for ODQ replication 
Message number: 018
Message text: Data for preview retrieved from source system
Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.
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The SAP error message CNV_IUUC_ODQ018 typically indicates that there is an issue related to data retrieval from the source system during a data migration or conversion process, particularly in the context of SAP Landscape Transformation (SLT) or SAP Data Services.
Cause: The error message CNV_IUUC_ODQ018 suggests that the system is attempting to retrieve data for preview purposes from the source system, but it may encounter issues such as: Connection Issues: There may be a problem with the connection between the source system and the target system. Data Availability: The data that is being requested for preview may not be available in the source system. Authorization Issues: The user or service account may not have the necessary permissions to access the data in the source system.
Configuration Issues: There may be misconfigurations in the data migration settings or in the SLT configuration. Performance Issues: The source system may be under heavy load, causing delays or timeouts in data
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