Solution : https://service.sap.com/sap/support/notes/1621799 (SAP Service marketplace login required)
Key words : 
toolbar buttons cutoff reason, sap@web installation guide 6, threadid=30366&tstart=0 sap integrated, rightmost toolbar button, visible toolbar area, listed support package, /3 support package schedule, sp patch level, sap developer network, sap service marketplace
Related Notes : 
       
| 1053737 | Expected release dates for SAP GUI for Windows & ITS Patches | 
| 563161 | SAP GUI, SAP ITS & SAP IGS patches on Service Marketplace | 
| 330793 | Downloading patches | 
| 97621 | OCS Info: Online Correction Support (OCS) | 
| 19466 | Downloading SAP kernel patches |