I have the same issue. Have a Ross tech hex +can cable & I've downloaded vagtacho & vag commander 3.6.
Is it an issue with windows 10? Can I not use the drivers that installed with vcds? I have a 2003 VW Passat B5 1.8t currently in what is called limpmode or fault code. What would be best to diagnose and clear the fault?
I sent my car to a little shop up the street to get diagnosed & the guy calls back asking if I have the skc because he wants to wipe or reset my ecm. I had already ordered the vcds & cable. I'm not really trusting what he's planning on doing. I believe he was going to hold off till I got the skc from VW America. Which from what I read I don't have a high probability of successfully retrieving from them. Also I do need to get the skc because I have 1 key. The car only came with the valet key. I have no keyless entry, no switchblade

Yes that I understand. If he wipes my ecm I may. Later on I will need it for keys, but for now what would be the best program to run to find what is causing the "limpmode" or to clear the fault to get my car out of it.

If hes deleting your eeprom and thinks that is going to fix your cars problem you need to find a new mechanic. it really sound like youre getting your self into a huge mess that you dont know anything about. Find a new mechanic or do some reading on this forum and learn yourself. once you do you see that what youre saying makes ZERO sense.
good luck