After more 2 000 000 (two million) views on forum for 1.5.0.x development versions... and 1.6.1.0, 1.6.3.0-dev versions
A new stable version, UltraVNC 1.6.4.0 and UltraVNC SC 1.6.4.0 have been released: https://forum.uvnc.com/viewtopic.php?t=38095
Feedback is always welcome

2025-12-05: Celebrating the 23th anniversary of the UltraVNC (26th anniversary since the laying of the foundation stone): https://forum.uvnc.com/viewtopic.php?t=38130

2025-12-03: Could you please complete our poll/survey? Renaming UltraVNC files and service to be more clear: https://forum.uvnc.com/viewtopic.php?t=38128
There was a problem to vote, it is solved now! Thanks in advance!

2025-12-02: We need help: English Wikipedia UltraVNC page has been requested to deletion: https://forum.uvnc.com/viewtopic.php?t=38127
Any help is welcome to improve the UltraVNC page and/or to comment on the Wikipedia Talk page

2025-05-06: Forum password change request: https://forum.uvnc.com/viewtopic.php?t=38078

2023-09-21: Important: Please update to latest version before to create a reply, a topic or an issue: https://forum.uvnc.com/viewtopic.php?t=37864

Development: UltraVNC development is always here... Any help is welcome
Feedback is welcome

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Protocol connection failed.

Single Click discussions / bugs
Post Reply
shur
Posts: 2
Joined: 2006-05-26 04:02

Protocol connection failed.

Post by shur »

Have SC installed - with 5 support options - when originally installed all 5 worked. Running vncviewer -listen 5501 . Network change - 3 internal ip addresses changed .. bang 3 out of 5 now report the following error. The remaining two support options work fine.
have read forum looking for ideas but most involve dsm plugin. running no encryption at this time. full install of Ultravnc on support pc's should not affect sc connectivity. working pc's only run vncviewer , other pc's have full ultravnc install?

Connection Failed - Invalid protocol!
Possible Causes:

-You've forgotten to select a DSMPlugin and the Server uses a DMSPlugin
-Viewer and Server are not compatible.
Bad connection.


have checked port forwarding on router. all changes have been updated on the three changed ip addresses. all ports match new internal ips and ports. Anything else. ports are open.

ideas?

thanks for your time .. Shur
kvarnon
Posts: 1
Joined: 2006-06-16 20:19
Location: St. Louis
Contact:

Post by kvarnon »

I have the same problem; usually on the second time they try to connect. I haven't found an answer, you?
Kevin Varnon
St. Louis, MO
sure
20
20
Posts: 42
Joined: 2006-06-05 15:02

Post by sure »

I have the same issue.
Try adding [DEBUG] in the helpdesk.txt
and suddenly it will work OK :/


Or try using the 1.0.1 vncviewer, I noticed the new one is not compatible with SC RL100.
Last edited by sure on 2006-06-29 12:08, edited 1 time in total.
shur
Posts: 2
Joined: 2006-05-26 04:02

Re: Protocol connection failed.

Post by shur »

Hello all, thanks for your time.
Yes have resolved the issue.
have 2 gateways on site , ip was correct internally but default gateway had been changed, changed over to the other gateway and presto. port forwarding was in effect and all is well.

Thansk again for your time.
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