Before solving the global stiffness matrix, a data check process is carried out to catch any invalid data. This includes a check of invalid material or section properties. If this kind of error is detected, the analysis is terminated and a message indicating the source of error is given. The user may need to return to the RAM Modeler to modify the member's material or section properties if this occurs.

During the solution process the analysis may be interrupted if a negative diagonal number (negative stiffness) is detected. This indicates an important stability problem that should be resolved. The program will provide an error message that should be helpful in identifying the source of the problem. This may include cases where all the members at a node are pinned for a specific degree of freedom. The user will likely need to return to the RAM Modeler to modify the model to enable it to be properly analyzed.

During the meshing, if the mesher fails to mesh the slab deck then the program gives the location at which the mesher encountered the error. It will also provide some directions on how to proceed to fix the problem. The user will likely need to return to the RAM Modeler to modify the model to enable it to be meshed successfully.

During the analysis, warning messages for local instabilities may be encountered. The local instability warning message indicates that a very small stiffness value is found (which usually results from incorrect section or material assignments, or improper release definitions at member ends located at a node). These stability problems are suppressed by providing a very small finite number at these locations in the global system stiffness matrix. However, it is strongly advised that the user check these warning messages and verify the validity of analysis results.

It is important to note that often the error messages provided will reference a node number or member number. The user should always be able to view the finite element model following an unsuccessful analysis to view the node numbers for the story where the analysis was terminated. Refer to Section 2.7.2 for information on viewing the finite element model following an analysis.