I need help to solve this ODE,

I didn't get series values F(k+3),Theta(k+2),phi(k+2),error comes in summation values.and

How to find the unknown parameters A,B,C.

 TLF.mw

Please Help,

I am trying to plot some movement equations, but the following error keeps happening:

Error, (in dsolve/numeric/process_input) system must be entered as a set/list of expressions/equations

when I tryed to rewrite the equation the error became:

Can someone help me with those errors?

Here is the code

pp.mw

Please Help!  The flow gets me like this,Where should i fix this problem.The flow changes for me fluctuate through the series range.What to do to get upflow in f(eta) and downflow in theta(eta)

 MVP.mw

 How to rectify the Error, (in MTM:-findsym) invalid input: a string/name list is expected for sort method `lexorder`   .Could you please help me to plot the curve.

TC1.mw

SS.mw

How to rectify this error,I want a downfall curve ,Please help.