Test before purchase UNO V1.3 fails with timeout.
Same happens with downloaded MidiMonitor.
Connection with UNO2 Control Center works perfect.
UNO2 version is V1.2
What is wrong with the test connection?

Maybe you have midi thru turned on when you are running the test.  I think it has to be off but I might have that backwards.

Sorry about that. The connection check is not compatible with UnO2 firmware. Since it doesn't make sense to do the test once more if you already have UnO2 firmware installed, I have adapted the purchase webpage. You can now skip the test when you have purchased UnO2 firmware before (you might need to refresh the webpage to get the latest version)