Software Restrictions for Linux Users

Some software applications in the CAEN Lab Software Environment (CLSE) for Linux have license terms that permit use only by individuals with a certain role at the University (e.g. a student enrolled in a course). If you have received an error message after attempting to run a software application on a CLSE Linux computer, it is likely either that your AFS token (the piece of data that authenticates your account to the environment) has expired, or that you do not have a required role at the University.

Refresh AFS Tokens

An AFS token is what CLSE Linux systems use to verify your identity and access to software licenses. When you log into a CLSE Linux computer, you are granted an AFS token automatically, but by default, the token expires after 25 hours. To refresh your token, type the following at a Linux command-line:


You will be prompted to provide your UMICH password. Once you have refreshed your token, attempt to run the software again. If errors persist, see below.

The Software Application May be Role-Restricted

If you have refreshed your AFS tokens and still do not have access to run an application, it is likely that the software license is restricted by an individual's role at the University (e.e. student, faculty, staff, etc.). Refer to CAEN Software Listings to determine which role(s) are eligible to use a given software application.

Individuals who would not otherwise be granted access to the instructional or research licenses of software may request access to individual applications in the CLSE. Complete this form to request access to a software application. CAEN administrators review all form submissions against license terms for the requested application(s), and grant access on a case-by-case basis according to eligibility and availability.