You can capture traces on the device, through Winscope, or through Android Debug Bridge (ADB) commands.

In Winscope, you can retrieve the most recently collected traces from a device during the previous session. This feature is especially helpful when facing connection issues, such as using ADB over Wi-Fi, or when Winscope closes unexpectedly. If there are no traces from the last session, Winscope displays No valid trace files found.

Error messages

Winscope shows the following messages during trace collection:

Message	Description
No trace targets selected	No trace checkboxes are selected.
Errors occurred during tracing: ERROR: INVALID_LAYER_STACK, please check your display state (must be on at start of trace)	A screen recording was requested, but the display was off at the start of trace.
Errors occurred during tracing: A specific error message received from adb command, such as Failed to find valid files for <trace types requested>	adb couldn't read the trace files, which typically happens when adb isn't running as root.
Errors occurred during tracing: Tracing time out	There's a connection issue with the device.
Errors occurred during tracing: {inner error}	This message covers all other errors.