Error: /home/patrick/.config/lite-xl/plugins/minimap.lua:538: invalid UTF-8 code

stack traceback:
	[C]: in function 'string.ufind'
	/home/patrick/.config/lite-xl/plugins/minimap.lua:538: in function 'plugins.minimap.draw'
	/usr/share/lite-xl/core/view.lua:304: in function 'core.view.draw_scrollbar'
	/usr/share/lite-xl/core/docview.lua:592: in upvalue 'old_draw'
	/usr/share/lite-xl/plugins/linewrapping.lua:529: in upvalue 'DocView_draw'
	/home/patrick/.config/lite-xl/plugins/lintplus/init.lua:532: in function 'core.docview.draw'
	/usr/share/lite-xl/core/node.lua:594: in function 'core.node.draw'
	/usr/share/lite-xl/core/node.lua:34: in function 'core.node.propagate'
	/usr/share/lite-xl/core/node.lua:599: in function 'core.node.draw'
	/usr/share/lite-xl/core/node.lua:33: in function 'core.node.propagate'
	...	(skipping 5 levels)
	/home/patrick/.config/lite-xl/libraries/widget/init.lua:1468: in upvalue 'draw'
	/usr/share/lite-xl/plugins/autocomplete.lua:598: in upvalue 'root_view_draw'
	/usr/share/lite-xl/plugins/contextmenu.lua:32: in upvalue 'root_view_draw'
	/home/patrick/.config/lite-xl/plugins/lsp/listbox.lua:520: in upvalue 'root_view_draw'
	/usr/share/lite-xl/plugins/treeview.lua:497: in function 'core.rootview.draw'
	/usr/share/lite-xl/core/init.lua:1356: in function 'core.step'
	/usr/share/lite-xl/core/init.lua:1416: in upvalue 'core_run'
	/home/patrick/.config/lite-xl/plugins/settings.lua:1896: in function 'core.run'
	(...tail calls...)
	[string "local core..."]:14: in function <[string "local core..."]:6>
	[C]: in function 'xpcall'
	[string "local core..."]:6: in main chunk