Mac - Microsofft App - client - unable to change or save credentials - can't access default keychain

FWIW, I was able to open "keychain access" then review the stored credentials in the login keychain.  For each credential stored for the rdp app, I was able to edit each item to grant access to the windows app. 

Within Keychain Access, select the default keychain, mine is login, select the credential needing fixed, Right click -> "get info", or highlight and press the (i) button and then select the "Access Control", click the "+" button, and add the "Windows App" and "Save Changes"

Windows App doesn't appear in any of my keychains. Is there any way to manually add it?

After "upgrading" to the latest Remote Desktop app on macOS -- now called "Windows App", you will not be able to save passwords as the app doesn't have access to your keychain for previously-stored passwords. 

To remedy this, expanding on what lawhonj said:

1. Open Keychain Access
2. Open the default keychain where your passwords are stored (usually called "login").
3. Search in the upper right for "com.microsoft.rdc.macos" -- this will show the stored password items.
4. For each item:
   1. Right click and select Get Info
   2. Click Access Control tab
   3. Click +
   4. Navigate to Applications and select Windows App
   5. Click Save Changes - this will require authentication.

fenbranklin
lawhonj 
Thank you for helping out the community, I will make sure these steps make it to public documentation! Quick clarifying question, did you install Microsoft Remote Desktop from App Center? As we would expect keychain inconsistencies since they App Center beta has different bundle ID than app downloaded through store