In Qlik Sense, if there is a virtual proxy setup with a prefix. The virtual proxy prefix will need to be added to all the data connections by modifying the connection string.
This issue can be detected when the monitoring apps reload fails. with the error below:
Error: QVX_UNEXPECTED_END_OF_DATA: Unexpected character encountered while parsing value: <. Path '', line 0, position 0"
In some situations, this issue may happen after upgrading to June 2017 release. The virtual proxy perfix will need to be added manually to the new data connections as the naming and the data connections has changed and entirely new data connections were introduced in June 2017 release.
Screenshots below show the old and new connection strings.
Edit each connection string and add the virtual proxy prefix then save the data connection.
Do the same for all the connections.
The screenshot below is missing the /test/
prefix. It will need to be added manually