Client with Outlook 2016 with iCloud add-on could not open Calendars. Got the following error:
The set of folders cannot be opened. An unexpected error has occurred. MAPI was unable to load the information service C:\PROGRA~2\COMMON~1\Apple\INTERN~1\APLZOD.dll. Be sure the service is correctly installed and configured.
Its related to iCloud not working. Googled it and there were some suggestions. Here is one.
Another suggestion it could be related to latest Outlook 2016 security update (KB3191932) for Outlook 2016 that came out June 14, 2017 but that was not installed. After trying a few things I had to repair iCloud for Programs and Features. Restarted. Went into iCloud settings and removed the sync to Outlook. Then enabled the sync to Outlook and it solved the problem.
I searched and searched until I came across the suggestion above that finally solved the problem.
1. Exit all applications on your computer
2. In the Control Panel launch “Programs and Features”
3. Find and select “Microsoft Outlook”
4. Choose CHANGE
5. Follow instructions to allow Microsoft to repair all Office applications on line
Be patient and let the routine run. It will take several minutes. When complete the APLZOD.dll problem (for me) was completely solved. The routine appears to have gone out to the internet to download APLZOD.dll. Anyway – – – it’s now reliably installed as an add-in in my Outlook application.
The other suggestions to also reload and re-initialize iCloud are also worth doing.