topic Re: Survey123 Adding Fields to an Existing Form Causes Error 500: "The service is locked because it is modified by another thread." in ArcGIS Survey123 Questions

Survey123 Adding Fields to an Existing Form Causes Error 500: "The service is locked because it is modified by another thread."

SaadShahzad — Wed, 08 Jul 2026 23:12:57 GMT

We've recently started experiencing an issue where adding a field to an existing Survey123 form will result in an endless publishing loop, logs show the following:

<15>1 2026-07-08T22:55:32Z HQD-GS245H4 ArcGISSurvey123Connect 25348 - [AppStudio@11205 category="qml" function="next" filename="PublishSurvey.qml" line="675"] qml: Adding to defintion: https://gis.blank.com/server/rest/admin/services/Hosted/service_a4ffc9999a4b44b1a58f6d2030d6b204/FeatureServer/0/addToDefinition { "fields": [ { "name": "standby_company", "alias": "Select Standby Company:", "type": "esriFieldTypeString", "length": 255, "editable": true, "visible": true, "domain": { "type": "codedValue", "name": "cvd_standby_company", "codedValues": [ { "name": "Great Bowl", "code": "Great Bowl" }, { "name": "Southwest Electric", "code": "Southwest Electric" } ] } } ] } <10>1 2026-07-08T22:55:36Z HQD-GS245H4 ArcGISSurvey123Connect 25348 - [AppStudio@11205 category="PortalRequest" function="onFailed" filename="PortalRequest.qml" line="149"] PortalRequest: PortalRequest failed url: https://gis.blank.com/server/rest/admin/services/Hosted/service_a4ffc9339a4b49b1a58f6d2000d6b204/FeatureServer/0/addToDefinition error: { "code": 500, "details": [], "message": "The service is locked because it is modified by another thread." }

We're experiencing this with every existing survey that has submissions in it, brand new surveys seem to publish just fine, but if we update those after publishing, it also results in the same error.

Just wondering if anyone else is seeing this issue?

Re: Survey123 Adding Fields to an Existing Form Causes Error 500: "The service is locked because it is modified by another thread."

abureaux — Tue, 14 Jul 2026 15:54:24 GMT

Not seen this partifular issue myself. Since you said this is happening with new content as well, I'm assuming you are testing on the same account. What permissions does this account have?

Are all the surveys in question very large? Does this issue happen with the default survey (the one created by S123 when you make a new survey)? Maybe try creating a new survey, change nothing in the two default questions, publish, then try to recreate the issue.

Have you tried validating the server itself (Log in to Portal > Settings > Servers. Also operationalhealth.py)?

Re: Survey123 Adding Fields to an Existing Form Causes Error 500: "The service is locked because it is modified by another thread."

ZacharySutherby — Tue, 21 Jul 2026 16:28:16 GMT

Hello @SaadShahzad,

It looks like you're using ArcGIS Enterprise, is your ArcGIS Enterprise (specifically ArcGIS Server) configured as highly available?

Would you also be able to provide what version of ArcGIS Enterprise you're using?

Re: Survey123 Adding Fields to an Existing Form Causes Error 500: "The service is locked because it is modified by another thread."

SaadShahzad — Thu, 30 Jul 2026 22:10:59 GMT

Hi Zachary, we're on 11.3. I believe we have a premium support ticket open with Esri (our IT team handles that), and I've been told the bug is related to BUG-000173561

We're currently awaiting a patch from Esri to resolve this.