200k edits with the same settings without problems for ~ one month. Same problem occured about a week ago.
We have a rare issue that pages get blanked on save.
We are unable to replicate the issue though it appears to happen occasionally to various users on various wikis. As best we can tell in the AWB code we are not sending blank text as the page text to be saved. So it could be a mediawiki API issue, though we've no evidence to know if that is the case.
As we have not been able to identify a root cause nor any reliable way to replicate the issue, we have no ideas as to how to solve it or make the issue less common.