The Sage ACT software can synchronize your Outlook calendar so that appointments and tasks appear in both programs. Sometimes a damaged folder or a missing system file can cause the sync to fail, even after proper setup, causing the error message "Calendar synchronization has failed." You can fix the problem by forcing the program to recreate the sync folder and manually registering the necessary system file.
Replacing the Sync Folder
Open the Task Manager by pressing "Control-Shift-Esc" and switch to the Processes tab. If you're on Windows 8 and don't see any tabs, click "More Details." Find the ACT sync process, which may appear as Act.Outlook.Sync.exe or Sage.ACT.Integration.exe, select it and press "End Process" (or "End Task" on Windows 8). Press "Windows-R," type "%appdata%\ACT\Act Data" (omitting quotes) and press "Enter." Rename the Outlook Sync folder to "Outlook SyncOLD" to force a recreation next time you run ACT.
System File Registration
Press "Windows-R" again, type "cmd" and press "Enter." At the prompt, type "cd "C:\Program Files\ACT\ACT for Windows"" (without the external quotes) and press "Enter." Afterwards, type "regsvr32 redemption.dll" (without quotes), press "Enter" and close the command prompt. Reopen ACT and try to sync again.