Error: Name is invalid (ERROR_MESSAGE_STATE)

Hi

We have recently migrated from EHP5 to EHP7.

Some of the ABAP webdynpro applications developed during EHP5 cannot be displayed in the system.

We have 2 clients.

It is running properly in 1 client, but not in the other.

The error we have is:

Any advice what may have been done/turned on correctly at another client, but not on the other?

Rgds

Rusyinni