With display_errors = On, I was getting a few warnings regarding session variables being reset. Now, I can not duplicate it. Maybe clearing the Xataface and browser caches resolved that (?)
I turned off display_errors and then I could log in (before that I was only getting the php warnings displayed, nothing else) and I then fixed the issue with intl module as below.
I still get repeated errors as:
[15-Jun-2021 20:27:00 UTC] PHP Warning: mkdir(): File exists in /home/rcf/public_html/finance/xataface/config.inc.php on line 43
Here is the error I was getting for not having the intl module installed. It was originating in my code:
[15-Jun-2021 19:18:39 UTC] PHP Fatal error: Uncaught Error: Class 'NumberFormatter' not found in /home/rcf/public_html/finance/MyPhpLibs/MyLibs_utilities.php:57
Stack trace:
#0 /home/rcf/public_html/finance/tables/RCF_Gifts/RCF_Gifts.php(32): MyLibs_getMoneyStr()
#1 /home/rcf/public_html/finance/xataface/Dataface/Record.php(2585): tables_RCF_Gifts->Amount__display()
#2 /home/rcf/public_html/finance/xataface/Dataface/Record.php(2909): Dataface_Record->display()
#3 /home/rcf/public_html/finance/xataface/Dataface/ResultList.php(135): Dataface_Record->preview()
#4 /home/rcf/public_html/finance/xataface/Dataface/ResultList.php(678): Dataface_ResultList->renderCell()
#5 /home/rcf/public_html/finance/xataface/Dataface/ResultList.php(315): Dataface_ResultList->toHtml()
#6 /home/rcf/public_html/finance/xataface/Dataface/SkinTool.php(1241): Dataface_ResultList->toHtml()
#7 /home/rcf/public_html/finance/templates_c/dataface/%%E4^E4B^E4B41A3D%%Dataface_List_View.html.php(42): Dataface_SkinTool->result_list()
#8 /home/rcf/public_html/finance/xataface/lib/Smarty/Sma in /home/rcf/public_html/finance/MyPhpLibs/MyLibs_utilities.php on line 57