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SAP GUI Installation -- Could not connect to host localhost on port 21212. (Firewall open and correct Java installed)

Former Member
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Thank you in advance for the additional help with my install - I appreciate it.

I have successfully installed everything now except for the GUI. When I attempt to do so I receive the following error:

Error while connecting to communication partner - see preceding messages.

Could not connect to host localhost on port 21212. Connection refused: connect Connection refused: connect

Not sure I understand where this is coming from as not only have I opened the correct ports - I have also opened my firewall to make doubly sure communication is open. Also, I have the correct Java installed.

Any help would be greatly appreciated.



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Answers (1)

Former Member
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During the installation, the default ports 21200 and 21212 are used for communication between SAPinst, GUI server, and SAPinst GUI. SAPinst uses port 21200 to communicate with the GUI server. The GUI server uses port 21212 to communicate with SAPinst GUI. You get an error message if one of these ports is already in use by another service. In that case,

Execute sapinst.exe with the following command line parameter:


For Example: sapinst.exe GUISERVER_DIALOG_PORT=21213