Getting this when preforming MV refresh:

2025-11-03 08:32:29.643Z WARN (starrocks-taskrun-pool-34|46767) [PartitionBasedMvRefreshProcessor.doRefreshMaterializedViewWithRetry():399]  [******] refresh mv failed at 1th time: com.starrocks.common.StarRocksException: Download file's checksum is not match backend [id=17126047] [
    at com.starrocks.qe.DefaultCoordinator.dealStatusToTryRetry(DefaultCoordinator.java:945)
    at com.starrocks.qe.DefaultCoordinator.handleErrorExecution(DefaultCoordinator.java:765)
    at com.starrocks.qe.scheduler.Deployer.waitForDeploymentCompletion(Deployer.java:309)
    at com.starrocks.qe.scheduler.Deployer.deployFragments(Deployer.java:171)
    at com.starrocks.qe.scheduler.dag.AllAtOnceExecutionSchedule.schedule(AllAtOnceExecutionSchedule.java:90)
    at com.starrocks.qe.DefaultCoordinator.deliverExecFragments(DefaultCoordinator.java:678)
    at com.starrocks.qe.DefaultCoordinator.startScheduling(DefaultCoordinator.java:573)
    at com.starrocks.qe.scheduler.Coordinator.exec(Coordinator.java:100)
    at com.starrocks.qe.StmtExecutor.handleDMLStmt(StmtExecutor.java:2538)
 [wrapped] com.starrocks.common.StarRocksException: Download file's checksum is not match backend [id=17126047] [
    at com.starrocks.qe.StmtExecutor.handleDMLStmt(StmtExecutor.java:2827)
    at com.starrocks.load.InsertOverwriteJobRunner.executeInsert(InsertOverwriteJobRunner.java:344)
    at com.starrocks.load.InsertOverwriteJobRunner.doLoad(InsertOverwriteJobRunner.java:169)
    at com.starrocks.load.InsertOverwriteJobRunner.handle(InsertOverwriteJobRunner.java:149)
    at com.starrocks.load.InsertOverwriteJobRunner.transferTo(InsertOverwriteJobRunner.java:212)
    at com.starrocks.load.InsertOverwriteJobRunner.prepare(InsertOverwriteJobRunner.java:256)
    at com.starrocks.load.InsertOverwriteJobRunner.handle(InsertOverwriteJobRunner.java:146)
    at com.starrocks.load.InsertOverwriteJobRunner.run(InsertOverwriteJobRunner.java:134)
    at com.starrocks.load.InsertOverwriteJobMgr.executeJob(InsertOverwriteJobMgr.java:90)
    at com.starrocks.qe.StmtExecutor.handleInsertOverwrite(StmtExecutor.java:2338)
    at com.starrocks.qe.StmtExecutor.handleDMLStmt(StmtExecutor.java:2431)
    at com.starrocks.qe.StmtExecutor.handleDMLStmtWithProfile(StmtExecutor.java:2347)
    at com.starrocks.scheduler.PartitionBasedMvRefreshProcessor.refreshMaterializedView(PartitionBasedMvRefreshProcessor.java:1147)
    at com.starrocks.scheduler.PartitionBasedMvRefreshProcessor.doRefreshMaterializedView(PartitionBasedMvRefreshProcessor.java:484)
    at com.starrocks.scheduler.PartitionBasedMvRefreshProcessor.doRefreshMaterializedViewWithRetry(PartitionBasedMvRefreshProcessor.java:390)
    at com.starrocks.scheduler.PartitionBasedMvRefreshProcessor.doMvRefresh(PartitionBasedMvRefreshProcessor.java:342)
    at com.starrocks.scheduler.PartitionBasedMvRefreshProcessor.processTaskRun(PartitionBasedMvRefreshProcessor.java:195)
    at com.starrocks.scheduler.TaskRun.executeTaskRun(TaskRun.java:352)
    at com.starrocks.scheduler.TaskRunExecutor.lambda$executeTaskRun$0(TaskRunExecutor.java:60)
    at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
    at java.base/java.lang.Thread.run(Thread.java:840)

I have seen this before. If you have a UDF based on external udf server, then drop and recreate them UDFs. Should resolve it.

Yes thank you! I figured it after few hours