I finally got a bug report. Now I know at least a few more people are using CasualConc.
The bugs are related to the recent changes I made to Lemmatization and Collocation.
The bug related to lemmatization was that when lemmatization was activated without specifying a lemma file, CasualConc crashed. This was because CasualConc looked for a lemma file when it started or returned from the preferences and if the file was not found, it crashed.
The two bugs related to collocation were 1) it didn't run in file mode, and 2) search in concord didn't work when 'Treat Keywords as One Word' option is activated in preferences. These should be fixed and work properly now.
I would appreciate any report of bugs. And I'd like to know how you like CasualConc.