Same problem in LR4 and in LR5: On startup, I get a long error message in computer code. The message appears over the LR screen as I last used it. I cannot do anything in LR because of the error message--not even choose File/Quit. I must Force Quit the application to do anything at all on my Mac, which is running OS 10.7.5.
Yesterday I upgraded to LR5 CC and was able to import my catalog from LR4 and use the app. I shut down normally and turned off the computer. Today I turned it on, opened LR5, and had the problem. And Adobe provides no weekend support!?!?
More info: The error message begins with:
An internal error has occurred.
html passed to JSON:decode(): <IDOCTYPE html PUBLIC*"-/W3C/DTD XHTML 1.0 Transistional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
The error message continues; it is so long that the code extends beyond the bottom of my screen.