xmlconvert | Comfortably converting XML documents to dataframes and vice

I want to get from XML file one or list of records from https://dchrs.com.pl/wp-content/themes/Lucid/doc/notowania.xml

Shortly XSD schema looks like:

Every time I want to run XslCompiledTransform.Transform, I get an exception due to invalid characters. One of such characters is e.g. "xFFFE".

How can I remove all invalid characters in C#?

XmlConvert.IsXmlChar doesn't work because here I check every single char and "xFFFE" as single char is not an invalid char.

I run into an exception always in XslCompiledTransform.Transfor but only if "xFFFE" is in the XML doc.

Here is the code:

I'm trying to read and transform many XML files into R data frames (or preferably Tibbles).

All R packages I've tried, unfortunately (XML, flatxml, xmlconvert) failed when I tried to convert the files using built-in functions (e.g. xmltodataframe from the XML Package and xml_to_df from the xmlconvert package), so I have to do it manually with XML2.

Here is my question with a small working example:

I am developing a Nuxtjs/Vuejs application to convert the XML->JSON and vice versa. Users can provide the values to the textarea and these textareas are managed by CodeMirror.

The textarea is bonded to V-model from the Vex Store. I have added Watchers on these Vuex state variables so whenever they change the values I want to convert the respective data to a different format. I.e if XML value changes then XML needs to be converted to JSON. Similarly if JSON value changes then JSON needs to be converted to XML.

When I copy-paste the XML into XML textarea then for the first time it works perfectly but I make any modification and try to introduce some Syntax error in XML then I run into the issue where the watchers starts calling each other and endup in endless loops.

I have provided the sample code within CodeSandbox: https://codesandbox.io/s/boring-water-g14zd?file=/pages/index.vue

Steps to recreate the issue:

1. Provide the Sample XML in the XML Area:

We're developing a bot that proactively messages people in a group chat. Bot mentions are showing blank on Desktop/Web chat view. Interestingly, on mobile and in the notification bar on the left, the full text does show correctly.

This issue may apply to other chats, but I have not tested.

I'm using similar code to the following Microsoft guide by constructing the mention object: https://docs.microsoft.com/en-us/microsoftteams/platform/bots/how-to/conversations/channel-and-group-conversations?tabs=dotnet#add-mentions-to-your-messages

Yes, I have tried using XMLConvert on the name as in the example, however, that does not make a difference, in fact, it puts the XML verbatim into the message sent by the bot.

I've also submitted a bug report here, as I suspect it's a bug in Teams itself (although, I could not find any other mentions of this or other similar example code): https://microsoftteams.uservoice.com/forums/555103-public/suggestions/43922577-bot-mentions-to-meetings-groups-are-blank-on-deskt

Relevant C# code:

I need to retrieve the attributes of the main node, but my code is not printing anything.

I'm facing an issue related to Spring Boot + data converters. So, basically I want to validate application/xml requests against xsd that are coming to an endpoint called /request/test.

My Configuration file

I have my local time in GMT +01:00 as the time of writing. I experience something, to me unexpected, when doing a ToString in the following way. Here we go:

Demonstrating the local system settings with +01:00 time zone (all these run green):

I have a function that reads XML from a Kafka topic into String format, which I then want to convert to a JSON Object.

Example XML: