This is a specific solution to the long-standing problem in bug 245482. To be properly portable it shouldn't be necessary to Google the problem every time "The trash has reached its maximum size! Cleanup the trash manually." appears. One way to work around that would be to integrate the trashcan into digiKam. Reproducible: Always
*** This bug has been marked as a duplicate of bug 224604 ***
This problem is relevant of digiKam trash files management. Since 5.0.0 we use an internal solution instead the desktop trash. It will never reproducible.