Hi Leslie,
Did you visit the /Setup/Default.aspx page?
I hope you got the code from the default branch not from my joedev branch.
That assertion error only happens in debug builds and it only happens if the stored procedure has a different number of parameters than expected by the code that executes it.
I know that the 2.3.7.7 upgrade script updated both the mp_Users_Insert and mp_Users_Update procedures but they do match the correct number of params an no errors happen for me. Parameters do get cached so its possible they were cached before you ran the update script and then it did not match. Touching Web.config should clear the cache and solve that.
But if you got the code from my branch before I merged the changes into the default branch then its possible you got an unfinished version of the 2.3.7.7 upgrade script that was missing the changes to those stored procs. Once it runs an upgrade script it will not run it again even if you later got the changes. But I know I did not change it after I pushed it to the default branch, I did commit it to my own branch before I was finished editing it though.
If all else fails you can copy the alter procedure statements from the 2.3.7.7 upgrade script and run it manually against your db.
located at /Setup/applications/mojoportal-core/SchemaUpgradeScripts/mssql/2.3.7.7.config
Hope that helps,
Joe