There is a bug with the current version of Visual Cron 5.7.5, when you try to retrieve the task log. It crashes Visual Cron on the client version all together and the server version retrieves the wrong task.
It seems this bug is fixed in version 5.7.8. How can I know if I can update my instance with the current license?

We constantly fix bugs and work with new functionality. We do not release "patches" for old versions.

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The question is - can I update my 5.7.5 to 5.7.8 or later version not buying the new license?

It depends on the current maintenance on your license. You can check this here:

http://www.visualcron.com/ActivationInfo.aspx 

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Thank you Henrik, that's exactly what I wanted. It says: "Valid to upgrade to version: 5.8.1 and versions that are published before 2012-07-13"
Where I can find instruction how to update my 5.7.5 to 5.8.1? Is exe doing everything automatically?

Yes, just make a backup for settings first.

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