GCODE Viewer slow, errors in Server Progress

What is the problem?
octoprint.printer.standard - ERROR - Exception while sending print progress to plugin octoprint_eta
Gcode Viewer is way behind actual Progress

What did you already try to solve it?

Logs (octoprint.log, serial.log or output on terminal tab at a minimum, browser error console if UI issue ... no logs, no support!)
octoprint.printer.standard - ERROR - Exception while sending print progress to plugin octoprint_eta
Traceback (most recent call last):
File "c:\octoprint\venv\lib\site-packages\octoprint\printer\standard.py", line 241, in call_plugins
plugin.on_print_progress(storage, filename, progress)
File "c:\octoprint\venv\lib\site-packages\octoprint_eta_init_.py", line 42, in on_print_progress
self.eta_string = self.calculate_ETA()
File "c:\octoprint\venv\lib\site-packages\octoprint_eta_init_.py", line 30, in calculate_ETA
strtime = format_time(finish_time)
File "c:\octoprint\venv\lib\site-packages\babel\dates.py", line 800, in format_time
format = get_time_format(format, locale=locale)
File "c:\octoprint\venv\lib\site-packages\babel\dates.py", line 411, in get_time_format
return Locale.parse(locale).time_formats[format]
AttributeError: 'NoneType' object has no attribute 'time_formats'

Additional information about your setup (OctoPrint version, OctoPi version, printer, firmware, browser, operating system, ... as much data as possible)
Octoprint Version is 1.4 latest, Printer: Ender 3 Pro, Firmware Marlin 2.0.4.4, Browser Firefox, OS Win 10 Pro, Ryzen 5 Maschine with 16GB Ram. Before upgrading to latest Version all was fine.

A post was merged into an existing topic: Curious issue with print progress