How do i solve this problem (i think it stops because of the capital A)?
There shouldn't be any problems at all with writing key sequences.
Can you send us the code you are using and some more information about your AUT (application under test) and your test environment (OS, Ranorex Version, ...)?
Which application are you trying to test, a website, a flash/flex application, or ...?
Can you also send us a Snapshot of the specific textbox?
Following link will show you how to generate a snapshot file:
http://www.ranorex.com/support/user-gui ... files.html
Could it be that the textbox does not accept longer strings, is limited to 16 input characters?
Can you manually input the specific string "123456789abcdefgABCDEFG+!?=" into your textbox?
Ranorex Support Team