Starting with macOS Mojave (10.14) and macOS Catalina (10.15), you must give the Screen Recording and Accessibility permissions to VNC Connect. If you do not grant these permissions you will see a blank screen in VNC Viewer and/or have view-only access.

Please follow the steps below to set up VNC Connect for macOS correctly. These steps must be done locally on the remote computer itself, they cannot be done remotely or via the command line.

Device Access

Screen Recording (fixes black screen) - Catalina (10.15) and later

1. Open System Preferences:
   
2. Click Security & Privacy:
   
   
3. Click Privacy:
   
   
4. Click Screen Recording:
   
5. Click the lock button to make changes, and then enter an administrator's username and password:
   
   
6. If vncagent is listed, place a check/tick next to it, and then click the lock icon again:
   
   Skip Step 7.
7. Otherwise, you will need to connect to VNC Server from VNC Viewer. Once you have connected, vncagent will appear in the list. Once vncagent is listed, go back to Step 6.

Accessibility (fixes view-only)

1. Open System Preferences:
   
2. Click Security & Privacy:
   
   
3. Click Privacy:
   
4. Click Accessibility:
   
5. Click the lock button to make changes, and then enter an administrator's username and password:
   
   
6. If vncagent is listed, place a check/tick next to it, and then click the lock icon again:
   
   Skip Step 7.
7. Otherwise, click the + button:
   
   then navigate to /Library/vnc/vncagent and select the Open button:
   
   and then click the lock icon again.

Instant Support

App is downloaded from the internet - Catalina (10.15) and later

You must specifically allow Instant Support to be opened on install as it is downloaded from the internet. 

Select open to allow the application to run.

App cannot be opened - software needs to be updated - Catalina (10.15) and later

The below message will appear if you are using a custom branded version of Instant Support.

To launch a branded instance of Instant Support, you need to follow the below steps.

1. Click OK to dismiss the warning.
2. Open System Preferences:
   
   
3. Click Security & Privacy:
   
4. Click General:
   
   
5. Click Open Anyway:
   
6. Click Open, as shown in https://help.realvnc.com/hc/en-us/articles/360002712837#app-is-downloaded-from-the-internet-0-4

Screen Recording (fixes black screen) - Catalina (10.15) and later

Your end users may see a prompt similar to the below when opening Instant Support. 

The end user will need to grant this permission so that you can view their screen.

1. Open System Preferences:
   
2. Click Security & Privacy:
   
   
3. Click Privacy:
   
   
4. Click Screen Recording:
   
5. Click the lock button to make changes, and then enter an administrator's username and password:
   
   
6. If Instant Support is listed, place a check/tick next to it, and then click the lock icon again:
   
   Skip Step 7.
7. Otherwise, you will need to connect to connect to the end user using Instant Support from VNC Viewer. Once you have connected, Instant Support will appear in the list. Once Instant Support is listed, go back to Step 6.

Accessibility (fixes view-only)

Your end users may see a prompt similar to the below when opening Instant Support. 

The end user will need to grant this permission so that you can control their screen.

1. Open System Preferences:
   
2. Click Security & Privacy:
   
   
3. Click Privacy:
   
4. Click Accessibility:
   
5. Click the lock button to make changes, and then enter an administrator's username and password:
   
   
6. If Instant Support is listed, place a check/tick next to it, and then click the lock icon again:
   
   Skip Step 7.
7. Otherwise, click the + button:
   
   then navigate to the location where the Instant Support app was downloaded (typically Downloads) and select the Open button:
   
   and then click the lock icon again.