I came upon this quite frequent issue with my XenDesktop 7.8 Hosted Shared Desktop environment based on Windows Server 2008 R2. Folder Redirection via GPO is in place, whereas Citrix User Profile Management is not used.
Exchange 2016 – Poor Outlook 2016 Performance – Troubleshooting

Exchange 2016 – Poor Outlook 2016 Performance – Troubleshooting – Server-side or Client-Side? Just recently I came across a newly installed Exchange 2016 environment and had to analyze a “poor performance issue”. I started my investigation by asking … Google! Of
Outlook 2007 and Exchange 2013/2016 – Keeps Prompting for Logon Credentials

After migrating to Exchange 2013 and/or 2016, and still having a couple of Microsoft Outlook 2007 installations left, the following issue started popping up: as soon as users launch their Outlook 2007 (while already being migrated to Exchange 2013/2016), they were
Microsoft KMS / VAMT v2.x and v3.x – Error 0x80070054 – Storage to process this request is not available

Just recently I came upon an Microsoft KMS error stating Error 0x80070054 – Storage to process this request is not available. This error was quite annoying as at first I didn’t had a clue what this was all about. The
Exchange 2013 / Outlook 2013 – Cannot open attachments, error “Excel experienced an error trying to open the file”

In case you try to open an attachment directly from within Outlook 2013 by double-clicking the corresponding Office file in the affected email, i.e. an .xlsx, .docx., or .pptx file extension, you might receive an error stating: Word experienced an
WorxMail – Access to your company network is not currently available

When launching WorxMail from your iOS device and running the initial configuration you might receive the following error after having entered your credentials and clicking Sign On: Access to your company network is not currently available:
Citrix Receiver 3.x and 4.x – Select an account to continue

When trying to connect to a XenDesktop 7.x and StoreFront 2.x based environment through NetScaler from an external Windows computer you could receive the following error upon finishing the Citrix Receiver initial wizard: Select an account to continue: