I am currently experiencing some difficulties with my dnn 4.5.5 installation. I had upgraded from dnn 4.5.0.

The installation is quite unstable with the following observations:
1. When I change module positions on the page for eg. from content to right pane the changes are not saved or show up intermittently normally after many error messages. For example, sometimes it will appear in the content pane and sometimes it will appear in the right pane.
2. Or if the the page name is changed using the page settings the new name does not appear or appears sometimes.
3. A common error message has to do with the view state (not sure what it means)
"A critical error has occurred.
Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request."

The whole thing is very frustrating and I am not sure what could be causing this.
Any help is appreciated.
Thanks