关于ABAQUS使用VUMAT？

编译了VUMAT，植入ABAQUS进行单元模拟，出现以下错文，请问是什么原因呢？

There is no element available in the model to control the stable time increment for Step 1. Please add a deformable element to control the stable time increment. Alternatively, you can use DIRECT TIME INCREMENTATION to perform the analysis at a user specified time increment.

Abaqus/Explicit Packager exited with an error - Please see the  status file for possible error messages if the file exists.