Solution
Currently, event channel names defined by XCPplus are not supported by ECUMC now.
A possible workaround is to use numbers for channel names in the A2L file.
For example, for the following event:
/begin EVENT
"task_5ms"
"5ms_c0"
0x0D
you would use "13" (the value 0x0D) instead of "task_5ms" for the event channel name.