If you're using the SCLogin module to login, please go to the parameters section and set the "Enable Caching" option to "None". We've seen on some sites where the SCLogin module's caching option can cause the security ID error when trying to login with Joomla credentials.I don't know why but I have selected "redirection page : current page" and when i try to log with my Joomla Pseudo/password the component redirect me on a random page, and i got "invalid security id"
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