Missing Upgrade Button - Problem sessions issue.

[daybuilder]

I am trying to upgrade from ZC v1.5.6c to v2.1.0. I was recommended to me in another post to attempt the Database-Only Upgrade method so I am following those instructions.

Steps taken: I uploaded a clean files installation of ZC v2.1.0 into a folder, and am attempting to attach my existing database to the new site files. Per the instructions of Database-Only Upgrade. I have ported over the 2 config files, matching my database name, user, and password same as was working before the upgrade, I merged the new data. Now I am running the zc_install or upgrade script.

Issue: The first step of the upgrade on the install page, does not have an upgrade button. I am sure the DB_PREFIX is correct as there is no prefix in my existing installation database. I also see this error: Some problems that need fixing before we continue. Problems with session support. I have also tried changing this setting in config files: define('SQL_CACHE_METHOD', ''); to define('SQL_CACHE_METHOD', 'database'); to see if that helps with the sessions notice.

I cannot get to the "Upgrade" option since the upgrade button is not showing. Not sure what to try next.