Several changes were applied to improve security. See ADV-2017-11 through ADV-2017-15 in Security Bulletins for more details.
Tabcmd export would fail if the URL to the view contained a dollar sign ($).
When you refreshed data in a view using the toolbar button, performance when reloading the view would sometimes be very slow.
If a workbook contained a Multiple Values (Custom List) filter, and was published with Prompt User authentication, an error would occur when the workbook was viewed in Tableau Server.
Published data sources containing custom SQL with parameters joined to other tables would fail to load with an error: Custom SQL relation refers to a non-existent parameter
When your Tableau Server language was set to a European language, or Japanese, it was not possible to add a user permissions rule to a published data source.
In some cases when you used a fixed axis, not all marks would be displayed after publishing the workbook to Tableau Server.
In workbooks containing a live file-based connection using a UNC path, and an extracted cross-database join connection that also included a UNC path based connection, refreshing the workbook extract would cause the standalone live file-based connection to fail to update.
In some cases old extracts were not correctly cleaned up, potentially resulting in low disk space issues.