Rest API services are not working on katalon

Found one bizarre error while executing Rest authenticate service. Below is the error log -

com.fasterxml.jackson.core.JsonParseException: Unexpected character (’<’ (code 60)): expected a valid value (JSON String, Number, Array, Object or token ‘null’, ‘true’ or ‘false’)
at [Source: (String)"

body.errorNotice { background-image:url(/3dspace/u"[truncated 1246 chars]; line: 4, column: 2] at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:1851) at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:707) at com.fasterxml.jackson.core.base.ParserMinimalBase._reportUnexpectedChar(ParserMinimalBase.java:632) at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._handleOddValue(ReaderBasedJsonParser.java:1947) at com.fasterxml.jackson.core.json.ReaderBasedJsonParser.nextToken(ReaderBasedJsonParser.java:776) at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:4662) at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4511) at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3466) at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3449) at com.fasterxml.jackson.databind.ObjectMapper$readValue.call(Unknown Source) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:136) at Script1626353614890.initialize(Script1626353614890.groovy:140) at Script1626353614890$initialize.callCurrent(Unknown Source) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:51) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:157) at Script1626353614890.run(Script1626353614890.groovy:65) at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194) at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119) at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:445) at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:436) at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:415) at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:407) at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:284) at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:142) at com.kms.katalon.core.keyword.builtin.CallTestCaseKeyword$_callTestCase_closure1.doCall(CallTestCaseKeyword.groovy:59) at com.kms.katalon.core.keyword.builtin.CallTestCaseKeyword$_callTestCase_closure1.call(CallTestCaseKeyword.groovy) at com.kms.katalon.core.keyword.internal.KeywordMain.runKeyword(KeywordMain.groovy:74) at com.kms.katalon.core.keyword.builtin.CallTestCaseKeyword.callTestCase(CallTestCaseKeyword.groovy:81) at com.kms.katalon.core.keyword.builtin.CallTestCaseKeyword.execute(CallTestCaseKeyword.groovy:44) at com.kms.katalon.core.keyword.internal.KeywordExecutor.executeKeywordForPlatform(KeywordExecutor.groovy:74) at com.kms.katalon.core.keyword.BuiltinKeywords.callTestCase(BuiltinKeywords.groovy:350) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325) at groovy.lang.MetaClassImpl.invokeStaticMethod(MetaClassImpl.java:1484) at org.codehaus.groovy.runtime.callsite.StaticMetaClassSite.call(StaticMetaClassSite.java:52) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:136) at com.nxp.katalon.testing.ws.keywords.util.WebServicesUtil.init(WebServicesUtil.groovy:67) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:98) at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1225) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1034) at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:822) at groovy.lang.DelegatingMetaClass.invokeMethod(DelegatingMetaClass.java:144) at com.nxp.katalon.testing.ws.keywords.util.WebServicesUtil.invokeMethod(WebServicesUtil.groovy) at com.kms.katalon.core.main.CustomKeywordDelegatingMetaClass.invokeStaticMethod(CustomKeywordDelegatingMetaClass.java:50) at org.codehaus.groovy.runtime.callsite.StaticMetaClassSite.call(StaticMetaClassSite.java:52) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:128) at Script1626413997471.run(Script1626413997471.groovy:59) at com.kms.katalon.core.main.ScriptEngine.run(ScriptEngine.java:194) at com.kms.katalon.core.main.ScriptEngine.runScriptAsRawText(ScriptEngine.java:119) at com.kms.katalon.core.main.TestCaseExecutor.runScript(TestCaseExecutor.java:445) at com.kms.katalon.core.main.TestCaseExecutor.doExecute(TestCaseExecutor.java:436) at com.kms.katalon.core.main.TestCaseExecutor.processExecutionPhase(TestCaseExecutor.java:415) at com.kms.katalon.core.main.TestCaseExecutor.accessMainPhase(TestCaseExecutor.java:407) at com.kms.katalon.core.main.TestCaseExecutor.execute(TestCaseExecutor.java:284) at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:142) at com.kms.katalon.core.main.TestCaseMain.runTestCase(TestCaseMain.java:133) at com.kms.katalon.core.main.TestCaseMain$runTestCase$0.call(Unknown Source) at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116) at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:152) at TempTestCase1653037558979.run(TempTestCase1653037558979.groovy:25) at groovy.lang.GroovyShell.runScriptOrMainOrTestOrRunnable(GroovyShell.java:263) at groovy.lang.GroovyShell.run(GroovyShell.java:507) at groovy.lang.GroovyShell.run(GroovyShell.java:496) at groovy.ui.GroovyMain.processOnce(GroovyMain.java:597) at groovy.ui.GroovyMain.run(GroovyMain.java:329) at groovy.ui.GroovyMain.process(GroovyMain.java:315) at groovy.ui.GroovyMain.processArgs(GroovyMain.java:134) at groovy.ui.GroovyMain.main(GroovyMain.java:114) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.groovy.tools.GroovyStarter.rootLoader(GroovyStarter.java:116) at org.codehaus.groovy.tools.GroovyStarter.main(GroovyStarter.java:138) Currently we have upgraded our instance (2021x). The same code worked fine for 2016x instance. I am wondering why it is throwing error for upgraded version. Any help would be appreciated! Thank You

Your code is expecting a JSON text responded, but actually the HTTP Response body contained some HTML or XML text.

I do not see why your target Rest API responded a HTML. I guess the response contained some message like

<p>invalid request, please check your client software.</p>