Q: SIMBL Install Failed

I recently upgraded my mini from OS X 10.11.5 to OS X 10.11.6 and I am now getting a message box stating:

"SIMBL install failed. Something went wrong, probably System Integrity Protection"

the console contains the following entries:

9/27/16 9:44:45.139 AM com.apple.xpc.launchd[1]: (net.culater.SIMBL.Agent) Please switch away from OnDemand to KeepAlive.

9/27/16 9:45:02.639 AM Dock[293]: Unable to create dictionary from bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle/Contents/Info.plist'

9/27/16 9:45:02.640 AM Dock[293]: Unable to load bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle'

9/27/16 9:45:02.769 AM cDockHelper[380]: SIMBL install failed

9/27/16 9:45:32.228 AM SIMBL Agent[336]: Unable to create dictionary from bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle/Contents/Info.plist'

9/27/16 9:45:32.229 AM SIMBL Agent[336]: Unable to load bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle'

9/27/16 9:48:25.563 AM SIMBL Agent[336]: Unable to create dictionary from bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle/Contents/Info.plist'

9/27/16 9:48:25.563 AM SIMBL Agent[336]: Unable to load bundle at path '/Library/Application Support/SIMBL/Plugins/Webroot.bundle'

Webroot is an antivirus package.

anyone have an idea what the problem might be?

thanks

John