The task you where trying to receive does not exist
This mostly is the result of a share task being interrupted. During this operation, a task was created, which is used for reference in the next operation. Since the share operation was interrupted, the server hasn't created the task, but the local workset still refers to it.
If you don't have important, unsaved changes in the workset, the quickest fix would be to disconnect the workset and download a new.
To fix this with the existing workset, you can:
exit Quadri for Windows/Novapoint
edit the worksets Server.xml file, which you find here: How to find server.xml.
reduce the value of "SynchronizationId" by 1
save
start Quadri for Windows/Novapoint and try again. If you can't open the workset, see: Opening workset.
If you get the same message, repeat this procedure a number of times! If it doesn't work after 10 attempts, contact Support with the server name, project name and the task id in the error message.
Example, if your server.xml file shows:
<SynchronizationId>315</SynchronizationId>
first try:
<SynchronizationId>314</SynchronizationId>
then:
<SynchronizationId>313</SynchronizationId>
etc