Session not opening and not responding

When I open any session in session manager, It suddenly closes and when I check my task manager I can see HeidiSql but not responding.

Perhaps HeidiSQL's main window is on another screen which is now disconnected?

You can try to reset the window positions:

Exit HeidiSQL, start regedit.exe and reset some values to their originals:

1. go to HKEY_CURRENT_USER\Software\HeidiSQL
2. delete all values starting with "MainWin", as shown in the attached image
3. restart HeidiSQL and hope to see it

still not responding i did create new session still not responding

My plan is to install latest version of HeidiSQL. What I fear is that the sessions cannot retained from the old version

That should not happen. If you fear of losing something you can make a backup, in HeidiSQL, under File > Export settings. Then, install the newer version. Don't uninstall the old one.

If HeidiSQL is still not responding then, please give it a few minutes to show. There seem to be sporadic file lock problems with auto-restored query tabs. v12.3 warns in such cases with a message dialog once the tabs are loaded.

I can only open session manager. If I click that Open button nothing happens sir.

Did you give it a few minutes, as told above?

yes sir i leave it for hours yet still not responding sir

Please

• just click "More" > "Export settings file" to create your mentioned backup
• then download and install HeidiSQL v12.3 from the download page.
• then try again if there's happening something when you click "Open"