Recently EPiServer has released two hotfixes to the CMS 6 R2 version, that bumps the version number up to 6.1.379.501. Although if you are running many sites on the same machine, different versions could cause some issues which they does in this case.
More information about how-to and what you should do can be found on the links on the right. I just wanted to put down the error that made me aware of the problem.
What really caused it was a missing row in the database, handling scheduled jobs. So by running the database schedule update script, it should be fine.
I should also make you aware of the fact that by running the intstallation files with the new version, it will affect other sites on that machine as well. So do it, but be aware that all sites on that machine should then be updated.
Exception - Column 'SecondsAfterLastPing' does not belong
Column 'SecondsAfterLastPing' does not belong to table Table.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.ArgumentException: Column 'SecondsAfterLastPing' does not belong to table Table.
[ArgumentException: Column 'SecondsAfterLastPing' does not belong to table Table.]
System.Data.DataRow.get_Item(String columnName) +3108760
EPiServer.DataAbstraction.ScheduledJob.Create(DataRow row) +1649
EPiServer.DataAbstraction.ScheduledJob.Load(String method, String typeName, String assemblyName) +76
EPiServer.UI.Admin.DatabaseJob.OnLoad(EventArgs e) +459
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3064