I’ll be honest, I’m new to this, so I apologize if my answers do not correctly address your questions..

As far as I can tell, the DataType is simply showing as “BaseDataType”–from this, should I assume that means that the server is not properly identifying it? I am able to read the values correctly/accurately, if that counts for anything (though I suspect…not particularly). The variable I am writing to should be able to accept a double and is a valid input, but any value I attempt to write (“0”, “1”, “0.0”, “1.5”, etc.) simply give the same error.

I can’t see a way to attach a picture, so to describe two screens by text:
When I try to write to a variable, I get the “Write value” popup, which prompts me for “New value:” and then has a field I can type into, followed by “Cancel” and “Write” buttons. I am not sure how to verify if it has a “proper value when I am writing”, as I’m not certain how to verify if my value is “proper”–it definitely is a valid value for the variable to take, and when I try to write to it, the variable is showing a reasonable value at that time, too.

When I view the attributes of the variable, it shows:

AccessLevel————-CurrentRead
ArrayDimensions——-Null
BrowseName————{A value, I believe not relevant}
DataType—————–BaseDataType
Description—————
DisplayName————{A value, I believe not relevant}
Historizing—————-false
Min.SamplingInterval–0.0
NodeClass—————-Variable
NodeId———————ns=2;s={A value, I believe not relevant}
UserAccessLevel——-CurrentRead
UserWriteMask———-
Value———————–{The correct value, currently an integer}
ValueRank—————-Any
WriteMask—————–

(Dashes added for clarity. No values show as “negative”/start with dashes, and a few lines do not seem to show a response)

The two things that jump out at me are the “BaseDataType” (which may be incorrect/might need to return Double?) and the AccessLevel/UserAccessLevel of “CurrentRead” (which might imply that it is not intended to be written to? Though again, the same variable can be written to from the desktop app if I specify write as double).