I have migrated several catalogs, and I uploaded some new photos and started a new album to the new Lightroom CC. But I have one catalog that will not migrate. I get a "Very useful" message that an error occurred and Adobe is very upset about it (yuck). They could have saved the cutsie stuff and taken a few additional keystrokes to actually tell me what the error was that occurred. They say to click a link for support which takes me to a web page. The web page lists a bunch of errors and tells me what to do in case of each error. Great... not a lot of help if you don't tell me what the error is....
Is there any way to dig through logs or something to try to figure out why this one catalog will not migrate? I have a software background and can go under the hood if necessary.
Sorry that you're having trouble migrating your catalog to Lightroom CC. May I know which exact error message are you getting while upgrading the catalog? Post a screenshot if possible.
Refer this article Known issues and workaround where we've listed all the known errors, issues and the workarounds related to catalog migration.