I've tried everything and can't get past this site settings bug in 2.6 (.net 4.6.2). I used the same machine key, everything upgraded as I always have and yet get an error on site setting page.
If I set <add key="EnableSiteSettingsSmtpSettings" value="false" /> then it works, but that's no good as I have a multi-site install. I've tried the upgrade multiple times with no luck.
Any ideas? Banging my head against the wall. Error is below.
2018-09-20 21:53:06,567 ERROR 65.30.35.12 - en-US - /Admin/SiteSettings.aspx - mojoPortal.Web.Global - Referrer(xxxxxxxxxxxxxxxxxxxxxxxxx) useragent Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:62.0) Gecko/20100101 Firefox/62.0
System.FormatException: The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.
at System.Convert.FromBase64_Decode(Char* startInputPtr, Int32 inputLength, Byte* startDestPtr, Int32 destLength)
at System.Convert.FromBase64CharPtr(Char* inputPtr, Int32 inputLength)
at System.Convert.FromBase64String(String s)
at mojoPortal.Web.mojoMembershipProvider.UnencodePassword(String pass, MembershipPasswordFormat passwordFormat)
at mojoPortal.Web.AdminUI.SiteSettingsPage.PopulateMailSettings()
at mojoPortal.Web.AdminUI.SiteSettingsPage.PopulateControls()
at mojoPortal.Web.AdminUI.SiteSettingsPage.Page_Load(Object sender, EventArgs e)
at System.Web.UI.Control.OnLoad(EventArgs e)
at mojoPortal.Web.mojoBasePage.OnLoad(EventArgs e)
at System.Web.UI.Control.LoadRecursive()