I tried to re-create my 4 well-tested USB device demos with 4.26. While HID mouse and MSC work flawlessly, two others do not work:
CDC - COM port shows in device manager but cannot be opened in terminal; same basic code (just a simple echo) works ok with 4.25.1 and 4.24 (broken PLL programming in 4.25).
HID keyboard - no data received.
I noticed that "custom HID" used for keyboard was heavily changed in 4.26, and the changes ar not good - DataIn callback was removed - bad .