Reason:  The Unknown error can be caused by a couple of different things. The error code will usually contain some information as to what might be wrong.

Error code: -5, No such feature exists

The most recently checked out KeyShot Studio feature (Pro, Enterprise, Personal Edition…) is no longer available on the server.

To resolve this, either check out a different feature, or contact customersuccess@keyshot.com to receive assistance.

Error Code: -83, Server FLEXlm version older than client’s

This error code is shown when the KeyShot License server is running a version that is too old for the KeyShot Studio Client.
To resolve the issue, follow the steps below.

1. Download the latest KeyShot License Server update.

2. Run the installer file and follow the prompts on the installation wizard. 

3. Launch the KeyShot License Server application and click New License to reload the license.

4. It is also a good idea to update KeyShot Studio itself. You can check for updates from the Help menu inside KeyShot Studio.

5. Once your server is up to date and running, KeyShot Studio will start properly.

Error code: -97, The desired vendor daemon is down

The KeyShot License server Vendor Daemon is either down or does not exist.

The two most common causes for this error is:

1. LUXION.exe is being blocked by a Firewall. To resolve this, check that your Firewall is not blocking C:\Program Files (x86)\KeyShot License Server\LUXION.exe.

2. The server that is being attempted to connect to, have a FLEXlm server running, but not for KeyShot Studio. Make sure the KeyShot License Server is running on the server machine. Please see here for instructions on installing the server.