This is an inconsistency with the way data is stored and returned by an LMS. This check was put in for LMS containers that used parameters on a url to send data. Once the limit was reached in various browsers data would be lost. We started checking to make sure what we saved is what we received back. Some LMSs had problems storing data and this was a sanity check.
We removed this in Lectora Online since it rarely a problem anymore.
In Lectora Desktop you can modify the support file trivantis.js to disable this error (see attached image). Set bDisplayError to false instead of true. This is the easiest way to disable this sanity check. The real underlying problem is that what we save to the LMS and what we receive back are not the same length. This may be because of some differing encoding being used but is is not the same issue where we would lose half of the data in the old days.
We will set the default for this to false in v18 since this is producing so many false positive error reports.