Incorrect BeginString (FIX.4.4) in c# (Quickfixn)

I'm trying to get the MarketData from fix, but I'm seemingly answering the "Incorrect BeginString (FIX.4.4)". The "Logon" returns OK. but when I call MarketDataRequest it doesn't work. I checked my XML dictionary and it's set to FIX.4.4.

quickfix C+ Incorrect BeginString with FIXT.1.1 and FIX.5.0 - FIX.5.0SP2

I saw a post like mine but my dictionary xml is declared as FIX.4.4 and also "LOGON" is working. so, I think a different case from the link above.

here is the log.

2020-11-10 17:27:44,148 [1] INFO  QuickFixDemo.Program OnCreate FIX.4.4:xxxxxxxxxxxxxxxx->XXXXXX
2020-11-10 17:27:46,321 [8] INFO  QuickFixDemo.Program ToAdmin 8=FIX.4.4|9=83|35=A|34=1|49=xxxxxxxxxxxxxxxx|52=20201110-08:27:46.309|56=XXXXXX|98=0|108=20|141=Y|10=112|
2020-11-10 17:27:46,666 [8] INFO  QuickFixDemo.Program FromAdmin 8=FIX.4.4|9=83|35=A|34=1|49=XXXXXX|52=20201110-08:27:46.437|56=xxxxxxxxxxxxxxxx|98=0|108=20|141=Y|10=114|
2020-11-10 17:27:46,681 [8] INFO  QuickFixDemo.Program OnLogon
2020-11-10 17:27:46,686 [8] INFO  QuickFixDemo.Program ToApp 8=FIX.4.4|9=126|35=V|34=2|49=xxxxxxxxxxxxxxxx|52=20201110-08:27:46.685|56=XXXXXX|262=0|263=1|264=0|265=0|146=1|48=4004|22=8|267=2|269=1|269=0|10=033|
2020-11-10 17:27:47,093 [8] INFO  QuickFixDemo.Program ToAdmin 8=FIX.4.4|9=100|35=5|34=3|49=xxxxxxxxxxxxxxxx|52=20201110-08:27:47.093|56=XXXXXX|58=Incorrect BeginString (FIX.4.4)|10=052|
2020-11-10 17:27:47,405 [8] INFO  QuickFixDemo.Program FromAdmin 8=FIX.4.4|9=65|35=5|34=3|49=XXXXXX|52=20201110-08:27:47.187|56=xxxxxxxxxxxxxxxx|10=038|
2020-11-10 17:27:47,426 [8] INFO  QuickFixDemo.Program OnLogout

my header of dictionary looks like this

<?xml version="1.0" encoding="UTF-8"?>

<fix major="4" minor="4" servicepack="0" type="FIX">
  <header>
    <field name="BeginString" required="Y"/>
    <field name="BodyLength" required="Y"/>
    <field name="MsgType" required="Y"/>
    <field name="SenderCompID" required="Y"/>
    <field name="TargetCompID" required="Y"/>
    <field name="MsgSeqNum" required="Y"/>
    <field name="PossDupFlag" required="N"/>
    <field name="PossResend" required="N"/>
    <field name="SendingTime" required="Y"/>
    <field name="OrigSendingTime" required="N"/>
  </header>

and my MarketDataRequest is like this:

<message name="MarketDataRequest" msgcat="app" msgtype="V">
  <field name="MDReqID" required="Y"/>
  <field name="SubscriptionRequestType" required="Y"/>
  <field name="MarketDepth" required="Y"/>
  <field name="MDUpdateType" required="N"/>
  <field name="AggregatedBook" required="N"/>
  <component name="MDReqGrp" required="Y"/>
  <component name="InstrmtMDReqGrp" required="Y"/>
</message>

my config

[DEFAULT]
BeginString=FIX.4.4
ConnectionType=initiator
ReconnectInterval=10
FileStorePath=store
FileLogPath=log
StartTime=00:00:00
EndTime=00:00:00
UseDataDictionary=Y
DataDictionary=./Fix/LMAX.xml
SocketConnectHost=fix-marketdata.london-demo.lmax.com
SocketConnectPort=443
SSLEnable=Y
SSLValidateCertificates=N
HeartBtInt=20

[SESSION]
# inherit ConnectionType, ReconnectInterval and SenderCompID from default
SenderCompID=XXXXXXXXXXX
TargetCompID=LMXBDM
Username=XXXXXXXXXXXXXXXXXXXXX
Password=XXXXXXXXXXXXXXXX
ResetOnLogon=Y

---------------- aditional information 2020/11/11

I debugged the quickfix and found the place where it is returning me "UnsupportedVersion exception". follow the image of my debugger.

DefaultMessageFactory's "this._factories" is empty. then this class returns to me the UnsupportedVersion... I'm researching the reason for this. Would you have any tips?

the problem was that in linux Directory.GetFiles is Case Sensitive, so DefaultMessageFactory:LoadLocalDlls() wasn't able to find the local dlls in Linux. I created the pull request in github https://github.com/connamara/quickfixn/pull/663 and with this change it worked perfectly in Linux.