Errors "TableauException" or "Could not find sheet with name: <SHEET>[0]" When Publishing a Workbook to Tableau Server or/and Tableau Cloud

Issue

After publishing a workbook, one of the following errors might occur:

Unknown server error
An unexpected error occurred. If you continue to receive this error please contact your Tableau Server Administrator.
Session ID ...
Would you like to reset the view?

or

Session Ended by Server: An unexpected error occurred. If you continue to receive this error please contact your Tableau Server Administrator. Session ID: SESSION <HTML> <HEAD> <TITLE> Service Unavailable </TITLE> </HEAD> <BODY> <H1> Service Unavailable - Zero size object

or

Uncaught Failed to re-initialize session

Additionally, you might experience one of the following errors:

TableauException: Error finding command parameter: yqf

or

InvalidSheetIdException: Could not find sheet with name: <SHEET>[0]

Environment

Tableau Server
Tableau Desktop
Tableau Cloud
Custom SQL

Resolution

There are a few possible workarounds:

Option 1

Open the workbook in Tableau Desktop and go to the Data Source tab.
Copy the original Custom SQL, without the extra line feed characters, into a text editor such as Notepad.
Remove the Custom SQL from Data Source Tab in Tableau Desktop.
Re-create Custom SQL in the Data Source Tab in Tableau Desktop with the text from step 2.
Re-do any field type conversions, such as a non-date to a date/datetime.
Create the worksheet and publish to Tableau Server.

For more information about changing the data type of the field, see Convert a Field to a Date Field in Tableau Help.

Option 2

Avoid using "<" symbol by changing the SQL statement. For example:

From: tableA.ActDate >= tableB.startDate AND tableA.ActDate <= tableB.endDate
To : tableA.ActDate BETWEEN tableB.startDate AND tableB.endDate

Option 3

Convert the date field that has a STRING data type to be DATE data type in SQL statement. For example:

TO_DATE(tableA.ActDate,'YYYY/MM/DD') as ActDate

Cause

When certain special characters, such as a “<” symbol, are used in Custom SQL, combined with a field data type change from a non-date to a date or datetime, extra line feed characters will be added at the beginning and end of the Custom SQL, as well as added after any other line feed characters that pre-existed.