Failure to take session ownership

Here are some basic troubleshooting procedures to follow to help solve problems with GAS session ownership.

An error message is displayed in the dispatch logs when the GAS fails to take ownership of the session:

Failed to update the session lock file: 
     /Applications/fourjs/gas/3.10/appdata/session/httpdispatch/session.owner.
[fail]
Failed to take session ownership

There are some things you need to check to troubleshoot the problem:

Did you start the GAS using a different account to the one you used the last time? If so, check that the new account has permission to access the session.owner file. To resolve, set the appropriate permissions to the session.owner file.
Have permissions been granted to create the session.owner file? To resolve, set the appropriate permissions to the session directory.
Do you have a multiple dispatcher configuration, and if so, is this the only GAS using this session directory? Check in the GAS configuration files xcf to ensure they are not starting with the same configuration for the session directories. See Why do my applications fail using multiple dispatchers?