The symptoms here are that the Modeler will just hang after a recorder is finished (using 100% CPU) or the created script will be missing bits, typically it won't have any of the required variables defined in the Definition section.
The problem is that the Gateway creates a badly formed intermediate recording (TOF) file if the content contains multiple consecutive ~ characters. This was first noted with a Cookie containing a '~~' sequence, which when encoded for SCL becomes '~~~~', but it is possible that consecutive ~s in many parts of the recorded HTTP stream can cause the same problem.
The same problem can be artificially created by using the Modeler Comment button whilst recording and typing in a string of more than 3 ~s.
Logged In: YES
user_id=19748
Originator: YES
A fix for this issue has been merged into the CVS HEAD. It
will become generally available in the OpenSTA 1.4.4 release.
gwhttp.dll: 1.4.4.5
OpenSTA: 1.4.4.7
This problem was fixed by avoiding the use of the '~~' string
to represent a single '~' when encoding SCL strings. Instead
the hex representation of ~<7E> is used. For the issue with
comments the problem strings are simply truncated to the
shortest sequence that does not cause a problem.