In Mobile Services, under "Manage Variables & Metrics" for an App when trying to save configuration, error message "matchFromAttribute <text> is invalid" is displayed.
The error is caused due to an invalid entry in Processing Rules defined for the report suite under Analytics Admin. For example, if a variable mapped in Processing Rule is disabled for the report suite, it becomes invalid for mapping in processing rule. This invalid mapping doesn't allow users to save any updates to Processing Rules without correcting it.
As Mobile Services configuration for "Manage Variables & Metrics" updates Processing Rules, the error message "matchFromAttribute <text> is invalid" is shown in Mobile Services if there is an incorrect mapping present in Processing Rules.
To resolve this issue, under Processing Rules update the incorrect mapping by using a valid variable or removing the incorrect mapping.