Scenario
SINCE 4.1.35 SINCE 4.2.0
The limits, Comment count limit and Comment char length limit, have moved from Profile Config > Issues into Profile Config > Project-mappings > edit project-mapping > email filters. However, the implementation of the limits has a bug that allows users to enter -1 values in the default project-mapping, which is an illegal character for the default project-mapping.
For more information on Comment count limit and Comment chars length limit, visit https://thepluginpeople.atlassian.net/wiki/spaces/JEMH/pages/3801939983/Email+Project+Mapping#Comment-count-limit
Work around for versions 4.1.35-4.1.41 and 4.2.0
A fix for the bug is in the works, i.e., soon -1 values for the limit will be prohibited; however, for the meantime, the work around is to not enter -1 as the CommentCountLimit and CommentMaxCharsLimit.
Fix for versions from 4.1.42 and from 4.2.1
SINCE 4.1.42 SINCE 4.2.1
-1 is no longer a valid value for CommentCountLimit and CommentMaxCharsLimit in the following versions:
4.1.42
4.2.1