3122653 - Every migration job cannot finish validation with job "/LTB/JOB_DISPATCHER" canceled

You are working with migration cockpit to do data migration. If you are working with LTMC, every time you clicked Start Transfer button, you got the loading bar stuck or "Step Validate Data is running on background (0%)". If you are working with Fiori app Migrate Your Data, any activity, like file validation, data simulation or migration cannot be started at all. This can happen to every migration object when such issue occurs. You also noticed 

• Stepuser has been maintained as per KBA 3094534 Migration job is stuck when there are still free jobs available
• In tcode SM37, job /LTB/JOB_DISPATCHER was canceled
  
• The job log of job /LTB/JOB_DISPATCHER shows the details, such as 
  Internal session terminated with a runtime error DBSQL_STMNT_TOO_LARGE (see ST22)
• In ST22, there is a dump generated as below
  
• Huge number of records exist in table /LTB/JOB_ERRORS on 10000+ level.

Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental.

• SAP S/4HANA 2020
  
  • LTMC (on premise) - Transferring Data Using Files
  • Migrate Your Data – Migration Cockpit
• SAP S/4HANA 2021
  
  • Migrate Your Data – Migration Cockpit
         

data migration, upload, stuck, hang, ltmc, start transfer, validate data, loading, dump/LTB/CL_JOB_QUEUE_ACCESS, job, cancelled , KBA , CA-LT-MC , S/4HANA Migration Cockpit , Problem