Altova Mapforce- Could not find start of message error

I am using Altomava Mapforce to map and load 837 x12 formatted text files directly to Sql Server 2014. I have correctly mapped everything except I get the following errors-

Missing field F142- Application Senders code
Could not find start of message with impl.convention reference '116731H333B2'. Message will be skipped.
Missing segment GE

I have included my header and footer information below from the original source text file. Does anyone know what is going on with the mapping, or if maybe there is something wrong with the data itself? Any help would be greatly appreciated.

Header-

ISA*11*          *11*          *PP*               *ZZ*20121143      *273041*0109*^*00501*000000000*0*T*:~GS*HC**211231153*20141121*1115*01*Y*116731H333B2~ST*837*2000001*116731H333B2~BHT*0029*00*0003000005*20141121*1115*CH

Message Data etc.......

Footer-

~SE*769*2000001~GE*1*01~IEA*1*000000000~

Solution

Your data is wrong. Here is a cleaned up version of the ISA / GS. For readability, I put a CR/LF after the segment terminator (~). Please note the ISA and GS do not indicate sender, which is going to cause all kinds of problems for auditing. See my comment above for analysis on the data per your bullet points.

ISA*11*          *11*          *PP*SENDER         *ZZ*20121143      *273041*0109*^*00501*000000000*0*T*:~
GS*HC*SENDER*211231153*20141121*1115*01*X*005010~
ST*837*2000001*116731H333B2~
BHT*0029*00*0003000005*20141121*1115*CH

An example of the enveloping:

ISA*00*          *00*          *ZZ*Test1Saver     *ZZ*RECEIVER       *151222*1932*U*00501*000111884*0*P*:~GS*HC*Test1Saver*RECEIVER*20151222*1932*1*X*005010~ST*850*0001~
...
~SE*8*0001~GE*1*1~IEA*1*000111884~