After upgrading from Matrix 2.5 to 2.5.4 (and then to 2.5.5 today), I am now getting errors when I save entries with Matrix fields. The error reads:
A PHP Error was encountered Severity: Notice Message: Undefined index: field_id Filename: matrix/ft.matrix.php Line Number: 2644
The site also runs Solspace Super Search 2.0.7.
ExpressionEngine version is 2.5.0
Anyone running into this issue?