The Invalid Public Screen Block error is issued in the following situations:
Public Screen Block <screen block> contains a parameter of record type <type> that is not declared as public: you have a Record parameter, in a public screen block, whose definition is not public.
You must set as public the Entity and/or Structure that belongs to the definition of the Record parameter.
Public Screen Block <screen block> contains a parameter of record type <type> that is a reference: you have a Record parameter, in a public screen block, with a definition where the underlying Entity and/or Structure is an eSpace reference. You can only expose elements whose owner is the current eSpace.
You must edit the public screen block, select the input parameter and use entities and/or structures owned by the current eSpace.
Arguments of '<type>' data type are not allowed in links from Public Screen Blocks: you have a public screen block with a link (screen reference, Link, or Button widget) whose Destination property has input parameters of either the Binary Data, Record, or List data type.
Depending on your requirements, do one of the following: edit the link and, if the input parameter is optional, do not map the respective Destination argument; or do not expose the screen block; or change the Destination input parameter data type. Learn more about input parameters.
Clicking the symbol will take you directly to the screen block reference offending property.
Expose a Screen Block | About Error Messages