Comment 1 for bug 914625

This error message means that whatever lava-tool used to be loading is no longer available (the actual module is gone)

What is the PATH you have on that machine? (when you say which lava-tool, what is the output)

Normally it's 100% safe to mix client side tools from debian packages and any number of lava-deployment-tool instances with any software as they don't interact in any way and are 100% isolated from each other. The downside is that you need to explicitly "ask" for an instance version by using the full path to the binary.