From the logs provided, A guess may be a locale issue and either an Invalid credential used to run the proxy service or the credential used to monitor the device.
Below; is a known list of unsupported characters;
umlaut characters: ä, ö, ü (most likely)
if this does not resolve your issue, It would require the following:
- Screen captures of the actual server failing,
- Balance version e.g. 188.8.131.52.220
- More complete logs.
- Is the proxy successful discovered under Discovery--> Proxies
- Are there servers being currently discovered via the proxy
Unfortunately, There is very little data for me to analyze much further.
If my replies are helpful or resolve the issue please take the time to mark the post as helpful or answered. Thank you!
OnCommand Insight SE