Edit my complicated UDF &I have a problem in recalculating it

Hello everybody
Before mentioning my question,I'd like to thank all members in this forum.you helped me alot in my questions.
>>>>>The UDF "Daysoffinwork_all" returns dates of attending in rest days and vacation days as follows:
1- attendaing in special rest days "Amr" or "Ramadan" or "Ashraf" or "Khaled".Their rest days are in table in cell "BI9"
2- attendaing in normal rest days of week like "Fri+Sat" or "Fri" or "thu+Fri" etc…
3- attendaing in vacation days which are written in cel "AP4"
The excelforum members assisted me to create this UDF with 3 codes.but I merged the three codes in unprofessional way.
Required:
1-Can you make the UDF more simple as I merged 3 codes?
2-The UDF returns dates but the they are not sorted.Can you sort the dates?
3-The problem I am experiencing now is that when I have my workbook open "calculate Addition_Req" together with another workbook (call it workbook 2), every time I make a change to workbook 2, all cells in "calculate Addition_Req" that call this UDF gets a #VALUE! error. Why is this happening?
I hope you help me