QDSMain.Exceptions.FailedDocumentCheckoutException: Failed to check out document with path

[#1]

We keep facing intermittent issues with below error for several Qlikview tasks. These jobs fail at times and succeeds few times. It cannot be permission issue since the job succeeds few times. Please advise.

8/10/2017 2:05:46 AM
Error Document open call failed. The document might require username and
password.

8/10/2017 2:05:46 AM Error The document failed to open.

8/10/2017 2:05:47 AM Error Document could not be opened

8/10/2017 2:05:47 AM Error The task "XXXXXXXXXXXXXXXXXXX" QDSMain.Exceptions.TaskFailedException: Task execution failed with errors to follow. ---> QDSMain.Exceptions.ReloadFailedException: Reload failed --->
QDSMain.Exceptions.FailedDocumentCheckoutException: Failed to check out
document with path: XXXXXXXXXXXXXXXXXXX at QDSMain.ReloadTask.Reload(String fileName, TaskResult
taskResult, String sectionAccessUserName, String sectionAccessPassword, eReloadOptions reloadOption, String variableName, String variableValue, Boolean moniterCpuUsage) --- End of inner exception stack trace --- at
QDSMain.ReloadTask.Reload(String fileName, TaskResult taskResult, String sectionAccessUserName, String sectionAccessPassword, eReloadOptions reloadOption, String variableName, String variableValue, Boolean
moniterCpuUsage) at QDSMain.DistributeTask.Execute(TaskResult currentTaskResult) --- End of inner exception stack trace --- at QDSMain.DistributeTask.Execute(TaskResult currentTaskResult) at
QDSMain.Task.AbstractTask.TaskExecution(ILogBucket logBucket, TaskResult taskResult)