Trinket M0 error while uploading a sketch

hello all. having some trouble understanding why this is happening. hoping someone can help. here is the error message:

Arduino: 1.8.6 (Windows 10), Board: “Adafruit Trinket M0”

PORTS {COM10, } / {COM10, } => {}
PORTS {COM10, } / {COM10, } => {}
Uploading using selected port: COM10
{runtime.tools.bossac-1.7.0.path}/bossac -i -d --port=COM10 -U true -i -e -w -v C:\Users\MIKE~1.SHA\AppData\Local\Temp\arduino_build_409002/simple.ino.bin -R
java.io.IOException: Cannot run program “{runtime.tools.bossac-1.7.0.path}/bossac”: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1048)
at processing.app.helpers.ProcessUtils.exec(ProcessUtils.java:26)
at cc.arduino.packages.Uploader.executeUploadCommand(Uploader.java:129)
at cc.arduino.packages.uploaders.SerialUploader.uploadUsingPreferences(SerialUploader.java:207)
at cc.arduino.UploaderUtils.upload(UploaderUtils.java:78)
at processing.app.SketchController.upload(SketchController.java:732)
at processing.app.SketchController.exportApplet(SketchController.java:703)
at processing.app.Editor$DefaultExportHandler.run(Editor.java:2030)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.(ProcessImpl.java:386)
at java.lang.ProcessImpl.start(ProcessImpl.java:137)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
… 8 more
An error occurred while uploading the sketch

Go back to board manager and install the Arduino SAMD board package. And make sure the Adafruit SAMD board package is also installed. Adafruit M0 boards require both SAMD packages.