ERROR: Execution of script 'Stylish Lite' failed! Failed to execute 'insertBefore' on 'Node'

Console log:

userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:4ERROR: Execution of script 'Stylish Lite' failed! Failed to execute 'insertBefore' on 'Node': Only one element on document allowed.(anonymous) @ userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:423:52:03.468 userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:4 Error: Failed to execute 'insertBefore' on 'Node': Only one element on document allowed.at eval (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:7)at Array.forEach ()at HTMLHtmlElement.eval (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:7)at eval (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:7)at X.every ()at X.each (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:7)at X.r.fn.(anonymous function) as afterat addStyle (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:245)at apply (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:235)at eval (userscript.html?id=d44da5ec-cf15-4657-976d-54722c8d97cb:261)

Tampermonkey BETA + Opera Stable