Clipboard not working in VMware Horizon? Here's why, and every fix

Why the clipboard does not cross into a Horizon session

A Horizon desktop is a remote machine drawn on your screen. Your local clipboard and the session's clipboard are two separate clipboards on two separate computers, and whether they synchronize is a redirected virtual channel that an administrator turns on or off. In Horizon that is the Configure clipboard redirection setting, delivered through the Horizon agent group policy templates. Related settings in the same clipboard policy template control which clipboard formats are permitted and how large a single copy-paste transfer may be.

Two consequences worth knowing, because they explain symptoms people usually misread as bugs:

• Redirection has a direction. The policy can be set to allow copy from client to server only, or server to client only. Plenty of regulated environments deliberately allow text in but not out, or the reverse. If paste works one way and not the other, that is configuration working exactly as designed, not a fault.
• Redirection has a size limit. A separate policy caps how much can move in one transfer. If short snippets cross fine but a long document silently fails, suspect the size cap before you suspect the application.

Note that VMware Horizon is now sold as Omnissa Horizon. Both names refer to the same product line, and both appear in current documentation and in the policy templates depending on version.

Fixes worth trying, in order

1. Disconnect and reconnect the session. Not minimize, disconnect. Clipboard channels wedge on long-lived sessions even when policy allows redirection. If copy-paste worked yesterday and died today, this fixes it more often than anything else.
2. Test each direction separately. Copy something local and paste it in; then copy something in the session and paste it out. Knowing which direction fails turns a vague ticket into a precise one, and tells you immediately whether you are looking at a one-way policy.
3. Test with a short snippet. If one word crosses and three pages do not, you are hitting the transfer size limit rather than a block.
4. Update Horizon Client. Old client builds have known clipboard bugs. If your endpoint is self-managed, update. If it is not, ask whether the client is current.
5. Ask your VDI administrator about the policy by name. The setting is Configure clipboard redirection, applied to the Horizon agent, and it is usually scoped per group rather than globally. Ask whether it can be enabled for your user group and in which direction. Environments running Dynamic Environment Manager can also apply it conditionally through Smart Policies, so the honest answer may be "it depends where you connect from."
6. If it broke right after an upgrade, mention the policy node migration. Horizon 2412 and later moved the group policy settings from the VMware nodes to the Omnissa nodes, and previously configured VMware settings do not migrate automatically. A clipboard policy that worked for years can stop applying until it is reconfigured in the new nodes. Admins appreciate the pointer.

Where the setting lives (for the admin you are asking)

The clipboard settings ship in the Horizon agent ADMX templates, in the clipboard-redirection template file, and appear in the Group Policy Management Editor under Computer Configuration, Policies, Administrative Templates, in the View Agent Configuration branch's Clipboard Redirection folder. The setting to enable full copy-paste is Configure clipboard redirection, set to enabled in both directions. If you are the user rather than the admin, that sentence is the entire content of the ticket you should raise.

The same problem, other names: RDP, Citrix, VDI

Every remote-access protocol treats the clipboard as an optional channel that can be switched off, which is why "clipboard not working in RDP" and "clipboard not working in Citrix" have the same shape as this page.

One check that saves an argument with the service desk: if the Remote Desktop Connection client is what you use, open Show Options, Local Resources, and confirm Clipboard is ticked before escalating. On a managed build that box is often greyed out, which is itself the answer.

When policy will not change: use the channel that is still open

Here is the asymmetry that makes a workaround possible. Administrators close the clipboard channel, but the keyboard channel is always open, because a remote desktop you cannot type into would be useless. Everything you type while the Horizon window has focus crosses into the session as keystrokes.

copypaster uses exactly that. It runs on your local machine, reads your local clipboard, the one that works, and types the text out as real OS-level keystrokes, pressing Enter at every line break and pacing itself like a person rather than dumping text instantly. Click into the field inside the session, and the text arrives through the keyboard channel. The remote application sees ordinary typing, because that is what it is. Nothing crosses the clipboard boundary, so redirection policy, direction limits and size caps never come into play.

A config file, a ticket write-up or a clinical note that would take ten minutes to retype into the session goes in hands-free with its structure intact. If the application inside the session also blocks paste at its own level, see getting text into locked-down apps. The typing approach covers both layers in one pass, which is why it is the usual answer for people fighting EMR fields delivered over VDI.

A note on policy

Clipboard redirection is usually disabled for data-loss-prevention reasons, and your organization may well have rules about what may move into or out of the environment. copypaster does not bypass authentication or access controls. It types text you already have into a field you can already click. But whether a given piece of text belongs in the session is your organization's call. If you are unsure, ask before you type it in, exactly as you would before reading it out and typing it by hand.