LR Classic fails to load completely. Why?

[tcguru]

LR Classic fails to load the Library module with the error message:

An error occurred when attempting to change modules.

The Develop module still works, bringing up the last photo I worked on but attempts to go back to the Library module end up with the same error message. The only workaround I've found so far is to restart the computer (running High Sierra) which is a royal pain. The LR Classic works -- until I shut it down. Then on restart of LR I get the bit about introducing me to LR, followed by the error message and the loop returns.

[Brad Lawryk]

You may want to try the Lightroom Classic CC forum for Classic CC specific help.