Are you still having trouble, m.may?
It appears to me from the /volume1/ bit of your error message that you are using a Windows IIS server. I’m afraid that my knowledge of Windows servers is very limited. It does appear that you are having permissions issues. I would try uploading the update again and if the issues persist than focus on permissions.
Another thing to consider: all of files mentioned in the error are unmodified core osTicket files. Therefore, whatever the issue is, I don’t have any reason to believe that it is necessarily related to osTicket Awesome. You may want to keep that in mind if you want to search Google using terms such as ‘osticket’ ‘IIS’ ‘permissions’ etc.
If your trouble persists you should do the following: open your installation in Chrome > open Dev Tools > go to Console tab and then copy/paste any messages into a reply.