Access denied error messages

If you get access denied, make sure that the user who is doing the upgrade has local Administrator rights.

Error message: Installation failed and was rollbacked...

When installing you may get the following error message: 
Installation failed and was rollbacked. [The process cannot access the file "c:\Inetpub\EPiServerNET\bin\episerver.dll" because it is being used by another process.]

One reason for this error could be security-related. The install operation requires that the account used to run the installation has read/write rights in the EPiServer installation directory.

• If you are logged on using an NT account the file rights of that account will be used to run the installation.
• If you are not using an NT account (for instance you are an extranet user) the ASPNET account is used, which means that the ASPNET account must have read/write rights.

Another reason for the problem is that the EPiServer scheduler doesn't release the episerver.dll. The solution to this is:

1. Stop the EPiServer Scheduler service manually
2. Reset IIS. If you do not want to reset IIS you can try to kill the aspnet_wp process instead (it will restart itself automatically).
3. Restart the product upgrade

If that doesn't solve the problem try this:

1. Reset the IIS or kill the aspnet_wp process.
2. Execute the installation program (EPiServerInstaller.exe)

License not valid?

You may get a "License not valid" message when upgrading an existing EPiServer 4.x installation using the installer application. But the site works without problems and you are sure that the license is valid. What is wrong?

The error is misleading and what it really means is that the installer can not contact the installation server. If you are connecting thru a proxy, turn off the proxy during the upgrade.