Layout error handling in Design Studio

Dear all,

Im bloody new to the Design Studio and after some tryouts (1.3 SP1) was interested in error handling regarding the layout area, something like this:

What I dont understand is: first, if such error messages are shown, there is no compelling appropriate exception in the error log, but it could be the case like for "too much data". What logic is SAP following here? How can I analyze and handle such errors, means also see the full exception text? Where can I find matching informations to concrete errors to be able to understand what is running wrong? Thank you in advance,

cheers