7.1.3 Miscellaneous Errors

ICD 4 is busy. Please wait for the current operation to finish.

Wait. Give the debugger time to finish any application tasks. Then try to deselect the debugger again.
Select
(Finish Debugger Session) to stop any running applications. Then try to deselect the debugger again.
Unplug the debugger from the computer. Then try to deselect the debugger again.
Shut down MPLAB X IDE.

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.