E-Notebook Enterprise: Trying to update the collections but gives a "System.OutOfMemory" exception.

If you had been working in the ELN while in Offline mode and have changed data 
1.1) log into an ELN admin account and navigate to your profile Offline folder and delete the unwanted sections/experiment?
2) If you do not have any data that needs to be sync to the Database, Try logging into the ELN admin account and deleted/empty the Offline folder.
2.1) you can also try deleting the "2.0" folder from c:/user/../appdata/ - which will also ask you to reinstall the ELN client on your machine (be prepared to reinstall the application)