# FAQ¶

When I run PSAMM it exits with the error “No solvers available”. How can I fix this?

This means that PSAMM is searching for a linear programming solver but was not able to find one. This can occur even when the Cplex solver is installed because the Cplex Python-bindings have to be installed separately from the main Cplex package (see Cplex). Also, if using a Virtualenv with Python, the Cplex Python-bindings must be installed in the Virtualenv. The bindings will not be available in the Virtualenv if they are installed globally.

To check whether the Cplex Python-bindings are correctly installed use the following command:

(env) \$ pip list


This will show a list of Python packages that are available. The package cplex will appear in this list if the Cplex Python-bindings are correctly installed. If the package does not appear in the list, follow the instuctions at Cplex to install the package.