ETNMINIM makes a very small ^ERRORS log with just 4 entries:  As *COM comment line, a *STACK,0,V,$H line containing the $HOROLOG system variable, a *STACK,0,V,$I line containing the $IO system variable, and a *STACK,0,V,$J line containing the $JOB system variable.  Normal ^ERROR logs created by ^%ETN usually contain 100s of entries, including many other entries other than *COM and *STACK..  Your Error Details displays Expression Value entries for the $H, $I and $J variables. and they all seem correct including a $H value of  67407,67118 which is a date of 07/21/2025 and a local time of  06:38:38PM.

The Error Details also displays a Process box containing "39452 01/06/1841 18 38-38 No: 82".  The job number (39452), time (18:38:38 ) and the Error ID (82) all seem correct but the Error Details seem to have incorrectly used the number 7 as the date value.

I have no experience with the Error Details display generated by the SMP web page.  Possibly that web page is decoding a *STACK entry (or some other *XXX entry) for the date that was not generated by ETNMINIM.  Since the %ETN logging failure was reported by error id 82 and there seems to exist an error id 81, it is possible that some useful information can be found by executing ZWRITE ^ERRORS(67407,81) in the LEARNING namespace.  Remember this particular ^ERRORS log entry was generated by a MERGE command that did not complete.

If an <INTERRUPT> occurs outside of the ^%ETN routine then ^%ETN ignores the interrupt and THROWs it back to the application code.

In this case the <INTERRUPT> occurs inside the ^%ETN routine while it is processing an earlier error signal.  At the line in question, ErrST+6, the ^%ETN is executing the
    Merge ^ERRORS(date,errnum)=^mtemp(State)
command which is merging the error state (in ^mtemp(State)) into the ^ERRORS(date,errnum) log variable.  That could mean that ^ERRORS(date,errnum) is only partially created so it would contain corrupted information about the error trap sent to ^%ETN.

It looks like that Merge got held up for some reason allowing the user time to signal <INTERRUPT> with a ctrl-C, or some other <INTERRUPT> signal.  That would cause ^%ETN to KILL  ^mtemp(state) and then ^%ETN executes the following local routine which generates a minimum entry in the ^ERROR log global entry describing the error that aborted ^%ETN.

ETNMINIM
 N h,d,i
 S h=$H,d=$E(h,"^",1),i=$I(^ERRORS(d))
 S ^ERRORS(d,i,"*COM")=h_","_$ZE_"; log entry lost."
 S ^ERRORS(d,i,"*STACK",0,"V","$H")=h,^("$I")=$I,^("$J")=$J
 Q

This mimimum ^ERRORS(date,count) entry describing the signal that interrupted ^%ETN should just follow the ^ERROR(date,count-1) entry that was only partially generated.

The zero date for the ObjectScript built-in $HOROLOG variable (aka $H) is 12/31/1840 so the date, 01/06,1841, you are seeing is date number 0 plus 7 days.  Now the $H day number in your Error Details, 67407,  is 07/21/2025 (i.e., today) and the $H time number (67118 seconds) is 06:38:38PM local time.

It looks like <INTERRUPT> was signaled while %ETN was generating the error log.  The <INTERRUPT> signal usually means someone typed control-C on the terminal.  The control-C may have interrupted %ETN before it had dumped all the date/time information of the original error.  The $H string in your Error Details, "67407,67118" is probably the date/time when the control-C was typed.

Your error message says the %DynamicArray class does not have a %GetAt method.  It has never had such a method although back in Caché 2016.1 there was an experimental array class that had a $getAt method.

You might try replacing all your .%GetAt(0) method calls with .%Get(0) method calls.

The default 'mindate' value for the $ZDATE(hdate,dformat,monthlist,yearopt,startwin,endwin,mindate,maxdate,erropt,localeopt)
system function call is 0, which represents 1840-12-31.  However, you can supply your own 'mindate' argument with negative values down -672045 which does date conversions more distantly into the past.

USER>zwrite $zdate(-672045,3,,,,,-672045)  
"0001-01-01"

which is Gregorian date January 1st in the year 0001 CE.  (That is the first day, in the first month in the first year of the first century.)  I should note that the Gregorian calendar was not in use back in the year 0001 CE but I don't think IRIS has support for Julius Caesar's calendar.  Passing a 'mindate' argument value more negative than -672045 will get you an <ILLEGAL VALUE> signal from $ZDATE() because there is some debate about whether the previous year is 0000 CE, -0001 CE or +0001 BCE.

$ZT is the abbreviation for the $ZTRAP system variable.  You learn more about it at https://docs.intersystems.com/iris20251/csp/docbook/Doc.View.cls?KEY=RCO... 

Setting SET $ZTRAP="^%ETSDK" will call a routine name  ^%ETSDK but I have no idea what the routine is.  Maybe it is a special Error Trap routine used at your site.

Executing
    SET $ZTRAP="^%ETN"
in an ObjectScript routine will setup the ^%ETN utility routine as an error trap routine which will catch an error signal and then dump the process state into the namespace before terminating the process.  Later, executing the DO ^%ERN utility will allow you to examine the various error trap dumps in a namespace.

If you are doing a moderate amount of computing between database access then there is no question that Python is faster then ObjectScript.  If you are doing heavy computing then a call out to C++ or C would be faster than both ObjectScript and Python.

But if you doing lots of database accesses with only simple string compares and string computations between each access then ObjectScript will usually be fastest because it is so close to the Globals engine that is doing all the accesses.

Generally, manipulation of strings in ObjectScript is reasonably good.  Parsing of JSON and XML is OK if you are using functions built into ObjectScript to do the parsing.  But if you are doing character-by-character parsing of complex data structures that are not supported by ObjectScript built-ins then it might be best to call out of ObjectScript to do that parsing.

An aside: when you have two $LIST values, L1 and L2 ,that you want to concatenate then you can just compute L1_L2 and string concatenation will do the job.  Some programmers loop over L2 one element at at time and add that element to the end of L1.  This can take n-squared time based on some product of the $LISTLENGTHs of L1 and L2.  Using string concatenation just depends on the sum on the lengths of L1 and L2.

Interestingly, for small examples, L<30, the first example is slower because it does both a $LISTBUILD plus a concatenation while the others just call a $LIST/$LISTUPDATE built-in.  But for large examples, L>1000, the first example can win by at least one order of magnitude because the other examples include execution steps that take O(L**2) time.

The %GetNext() method calls in the HS.FHIR.DTL.Util.JSON.Adapter class must have been written using 2 arguments and looking something like
   while iter.%GetNext(.Name, .Value) {

When the two argument form of %GetNext encounters a %String value, it always return an ObjectScript string in the 2nd argument which limits the string length to 3641144 characters.  However, there is a 3 argument form of %GetNext(.Name, .Value, .Type) which never signals <MAXSTRING>.  If a string element in a %DynamicArray/%DynamicObject (%DA/%DO) element is too long then a %Stream oref is returned in the .Value argument while the .Type argument variable contains the value "string".  If .Type is not "string" but is instead "oref" then that tells you the element in the %DA/%DO was originally a %Stream oref and not a %String value.  See the Class Reference web page describing the %Iterator.Object class which will explain how to use the 3rd .Type argument to solve ambiguities that occur when %GetNext must convert the %DA/DO value returned in .Value to an ObjectScript value different from the original JSON value.

You should suggest to HealthShare developers that their HS.FHIR.DTL.Util.JSON.Adapter class (and maybe some other classes) should be using the 3 argument form of %GetNext(.Name,.Value,.Type) instead of the 2 argument form %GetNext(.Name,.Value) in order to eliminate possible <MAXSTRING> and <MAXNUMBER> errors.

Is the file you are editing in IRISLIB or some other Read-Only database?  If so, use the System Management Portal (SMP) to turn off the database Read-Only option.

I am not sure exactly what you want to do.  Is check1 just an ordinary string, or might it sometimes be a string that starts with a number (like a %Status variable)?

The unary plus operator (+) turns a string operand into a number.  If the string starts with the syntax of a number then +string returns that number and ignores characters in the string following the numeric syntax.  If the string does not start with a number (this includes the empty string) then +string returns 0.  It is possible for +string to signal <MAXNUMBER> if the characters at the beginning of string are too large for conversion to the computational numbers supported by ObjectScript.

You could try
  ret:+check1 check1
which would return check1 only if it were a non-empty string that starts with a non-zero number.

If you want to return a string value that could be tested as a boolean that you have to append "1" to the front of the string if +string=0 is true.

The Class Reference pages for IRIS, available in any IRIS installation, describe all the classes installed in the installation.  The Class Reference for the %Regex.Matcher class documents that the %Regex.Matcher class comes from the International Components for Unicode (ICU). The ICU maintains web pages at https://icu.unicode.org .  The class reference documentation also contains the following statement for ICU documentation specific to the IRIS %Regex:

{quote}The definition and features of the ICU regular expression package can be found in https://unicode-org.github.io/icu/userguide/strings/regexp.html .{quote}

Additional documentation on the Unicode Regex package specific to how it interacts with the Unicode character set can be found at https://www.unicode.org/reports/tr18/ .

A quick comment on performance.  A TRY ... CATCH is very efficient at run time if no exception occurs.  The only extra code that is executed is a jump at the at end of the TRY block to go around the CATCH block.  However, TRY ... CATCH is slower than using the %ZTRAP when an execption does occur.  At compile time TRY ... CATCH blocks build tables that include program counters that describe which object code locations are in each TRY block and where the corresponding CATCH block begins.  When an error is signaled (or THROWn) at run time, it is necessary to scan the frame stack searching the compile-time generated TRY ... CATCH tables to find the CATCH location to go to after popping the intermediate stack frames.  If there are no TRY ... CATCH blocks involved then it is usually faster to just jump to the most recent setting of the $ZTRAP variable.

When exceptions are "exceptional"  then TRY ... CATCH is most efficient since it avoids pushing $ZTRAP value in preparation for handling an exception and it also avoids popping the $ZTRAP value when the exception does not occur.  If exceptions are part of a usual, successful, and often executed code path then it might be better to use $ZTRAP to catch those frequently executed signals.

The %DynamicAbstractObject (%DAO) subclasses, including the %DynamicArray and %DynamicObject classes, provide the best way to read/send JSON representation into/out-of IRIS databases.

The %FromJSON method can create a tree of %DAO objects from external JSON representation.  Then elements of %DAO data can be read or accessed using ObjectScript property syntax and using methods like %Get and %GetIterator.

Data inside an IRIS database can be used to build a tree of %DAO objects by using the ObjectScript JSON constructor syntax, property assignment statements and using methods like %Set and %Push.  If all you do is store values into previously undefined elements of a %DAO object then the performance is usually quite good.  Then that %DAO tree can be turned into JSON representation using the %ToJSON method.

It is not recommended that data in a tree of %DAO objects be extensively and repetitively modified/updated by the %Set method or by other ways that can modify data in a %DAO.  This is especially true if you are repetitively changing the size of data elements.  In such cases, the data in %DAO objects should be extracted and converted to some other optimized database structure.  Often this can be Relational DataBase access if a mix of rectangular arrays provides the desirable access.  It can be a %Stream if sequential access is needed.  If a number of data elements are to be searched then columnar vectors can be used.  IRIS can supply all these other access methods by layering them on top of ObjectScript multi-dimensional arrays.  The IRIS multi-dimensional arrays (both global and local) provide the best tradeoffs across a large variety of differently ordered read/write/update/modification operations.

If you have data in a %DAO tree and you need to make small or infrequent modifications of the data then it is acceptable to leave it in %DAO representation.  You can also make repetitive reads of %DAO data without needing to convert to some other representation.  But otherwise, %DAO objects are best limited to moving data into and out-of JSON representation.

Assuming  that response.message_code is part of an ObjectScript expression then you want to evaluate response."message_code" because _ is an ObjectScript operator so you must quote "message_code" to change it into a method or property name.  Otherwise, _ is the string concatenation operator so the value of response.message will be concatenated with the value of code.