I was using Zscaler and Microsoft Remote Desktop to connect few remote VDI (Virtual Desktop Infrastructures), and everything was working fine before. However, I got an ugly error like one above one day.
Since I will have an important meeting up coming up on Monday (today is Saturday) that needs to be connected to one of these VDIs, this became a personal urgent issue that needs to be resolved as soon as possible. I created a tech support ticket in Friday, but a tech support personnel messaged me through WebEx chat saying that he could not find a problem because he could ping and RDP into these machines. One other coworker faced a same issue, but others also notified that they have no problem connecting to do these machines.
After some struggles, I found an internal Yammer channel and posted this issue. Somebody replied, and what seems to be problem was with ZScaler version issue. His shared screenshot showed that he was using Zscaler version 3.2.3.17 (281392), which is exactly the same version I was using.
After doing some research by looking at past Yammer posts and some Googling, I found out that there is a new ZScaler version that might come with a possible fix for this problem.
But when I clicked Update App button located in Zscaler > About, it said that my Zscaler is up-to-date. Dang.
So, I was looking for a manual download link, and I found out this official page from ZScaler as seen in below picture. Oops. This was a wrong instruction, and it was only for mobile application with a same name.
I went back to company's instruction manual and noticed that the direct download ZScaler link was version 2.2.4.0 (261629). I have no idea how or when did I end up downloading 3.2.3.17 (281392) in first place, but I just followed this instruction and downgraded to 2.2.4.0 (261629).
I logged out from ZScaler's connection, and I tried to connect to those VDIs again. Nope, it did not fix it. I tried to turn off my Firewall and tried again. This did not work either.
After few more Google search, configuration problem on the Windows Remote Desktop Gateway server seems to be an issue. Microsoft did not seem to write their Remote Desktop Mac Client to read all the settings, which is Gateway Server information. Thus, the solution is to statically configure the connection in the Mac RDP client.
STEP 1: Go to Preferences in Remote Desktop Mac client
In Mac, go to top to select Microsoft Remote Desktop, and click Preferences.
STEP 2: Add a new Gateway
You need to get this information from your team. Gateway name should be host name or IP of your company's broadband connection.
STEP 3: Edit option for your VDI
Select one of your VDI and go to Edit by Control + click Touchpad.
STEP 4: Select Gateway you created
Select a Gateway that you created in Gateway dropdown list.
STEP 5: Try to connect again
Try to reconnect to your VDI again, and it should not throw that error anymore and let you connect to your work VDI!
