EHP 7 Upgrade - Position 99999999 isn't in table T528B

Question

We recently upgraded to ECC 6 EHP 7 and noticed that we can no longer create personnel records. We don't use HCM for anything other than creating our sales reps as personnel numbers.
In our non-upgraded system we're able to create a personnel # without issue but in our EHP 7 system it returns error message "Entry S 99999999 does not exist in T528B (check entries)". Sure enough the position isn't in table T528B but it never has been.  At this point we're not sure if the issue is that the Position is missing or if it's a related Personnel SubArea issue. In our non-upgraded system a Personnel Sub Area of 1000 is defaulted through a Dynamic Action but in EHP 7 it no longer seems to be getting populated. The field is greyed out so I can't enter it manually but nothing is entered.
We have gone to OSS and have been given several pieces of advice, none of which has worked. First off we were instructed to maintain an actual position as the default. That didn't work.
To do this I went to SM30 and for table T77S0 and for the PLOGI PRELI
value tried to replace 99999999 with 50000138. The system returns an
error of which the long text is:
Specify a valid value
Message no. 5B190
Diagnosis
No position which actually exists in PD (in the file PLOG) may be
entered as a 'default position', since it only displays a symbolic
position.
1. If you are editing the entry PLOGI PLOGI:
The entry PLOGI PRELI already contains a position number which
exists in
the required plan version. Please cancel your entry.
Before entering the plan version, you must enter a position number
according to PLOGI PRELI that does not already exist in this plan
version.
2. If you are editing the entry PLOGI PRELI:
Please enter a value for which no position was created in the
integration plan version (you will find this in T77S0 - entry PLOGI PLOGI); Also check whether the PLOGI PLOGI entry is correct.
Next we were asked to populate the BTRTL value through user exit ZXPADU01 however that only can change data in structures PREL and PREF neither of which has BTRTL in it.
A popular solution on SCN seems to be the use of dynamic actions, which we did actually use but OSS has come back and said "
The value is getting pushed in both ofyour systems by a dynamic action in table V_T588Z. Unfortunatley thiskind of propsing default values is not the correct way and is working in your TRN system accidently. Dynamic actions are designated for creating Infotypes dynamically during any action but are not suitable for updating Infotype 0001 with default values.
At the end of the day none of us have any real experience with HR/HCM as the only thing we use it for is creating sales reps as personnel #'s and it's been working fine for the past 15 years.  Now all of a sudden we upgrade to EHP 7 and it doesn't seem to work and the normally suggested solution that is on SCN seems to no longer work and neither do OSS's solution.  Can anyone help us default in the Personnel Sub Area when creating a new Personnel # through PAL1.  I'm not 100% sure that will cause the 9999999 default position issue but I have a feeling it will, or at the very least get us past one part of the problem.
Is there a valid user exit that we can default BTRTL through or some other way? I read another SCN thread that stated "The Position will often default the Personnel Area and Personnel Sub-Area in IT0001, from it's IT1008 values." but don't know really what IT0001 or IT1008 is and additionally wonder if the default position of 99999999, again which doesn't exist in T528B could be edited.  Any help is greatly appreciated and please be as detailed as possible as we literally have no first hand experience with any part of HCM.
Sincerely,
David

Answer 1

Thanks Maheswaran!!!
Yesterday I reviewed dozens of notes and seems I missed 1317551, this is SAP answer for my issue. Second one - 1278517 - and many others I read yesterday.
Yesterday I found one 334477 (from 2001) which also confirmed my point of view.
What for I need these entries - just to process my current processes. Problem is that someone how developed this piece of code forgot to check whether functionality is activated and then call function. In my case I just need these entries to go through that function (without error). Afterwards there is a check of flag in requisition, but it's always empty as I don't use it. Anyway logic in SAP is something confusing and hard to explain it.
You make my day – thank you for that.. I can close thread unless you have something to add?
Regards
Bartlomiej