Access to VSIX-Temp is Denied

[DavidCurd]

Describe the bug
The ALOps App Compiler step will intermittently fail with an error such as:

##[error]Access to the path 'C:\bcartifacts.cache\sandbox\27.4.45366.46217\VSIX-Temp' is denied.

This appears to be the same issue as previously logged here:
#400

We've seen errors like this since we started using ALOps, but they are now more frequent as we run more builds.

the used yaml

  - task: ALOpsAppCompiler@2
    displayName: ALOps App Compiler - Weekly Build
    condition: and(succeeded(), eq(variables['Build.SourceBranchName'], 'dev'),eq('${{ parameters.artifactVersion }}', 'default'), eq(variables['artifactTypeVar'], 'sandbox'))
    enabled: true
    inputs:
      artifacttype: $(artifactTypeVar)
      versionSelect: Weekly
      artifactcountry: ${{ parameters.artifactCountry }}
      accept_insider_eula: true
      appversiontemplate:  ?.?.?.?
      publishartifact: false
      pwsh: ${{ parameters.useLatestPowershell }}

the output

2026-02-16T12:00:44.2584375Z ##[section]Starting: ALOps App Compiler - Weekly Build
2026-02-16T12:00:44.2598258Z ==============================================================================
2026-02-16T12:00:44.2598440Z Task         : ALOps App Compiler
2026-02-16T12:00:44.2598536Z Description  : Compile AL Extension(s) for Business Central
2026-02-16T12:00:44.2598677Z Version      : 2.0.10523
2026-02-16T12:00:44.2598770Z Author       : Hodor
2026-02-16T12:00:44.2598887Z Help         : Compile Business Central extension(s) from AL code.
2026-02-16T12:00:44.2599030Z ==============================================================================
2026-02-16T12:00:46.9216095Z *** Using Powershell 7
2026-02-16T12:00:49.4006330Z ******************************************************************************
2026-02-16T12:00:49.4014032Z *** ALOps v2 - Preview                                                     ***
2026-02-16T12:00:49.4023532Z ******************************************************************************
2026-02-16T12:00:49.4239053Z *** Importing required ALOps-Functions
2026-02-16T12:00:49.8363354Z *** Task Inputs:
2026-02-16T12:00:49.8418070Z 
2026-02-16T12:00:49.8640800Z �[32;1mname                                            �[0m�[32;1m value�[0m
2026-02-16T12:00:49.8641503Z �[32;1m----                                            �[0m �[32;1m-----�[0m
2026-02-16T12:00:49.8641757Z artifactversion                                  
2026-02-16T12:00:49.8642013Z artifacttype                                     sandbox
2026-02-16T12:00:49.8642245Z artifactcountry                                  GB
2026-02-16T12:00:49.8642478Z versionselect                                    Weekly
2026-02-16T12:00:49.8642716Z updateruntime                                    
2026-02-16T12:00:49.8642943Z alternativeartifacturl                           
2026-02-16T12:00:49.8643172Z alternativevsixurl                               
2026-02-16T12:00:49.8643563Z vsix_cache_hours                                 0
2026-02-16T12:00:49.8643828Z alsourcepath                                     C:\agents\_work\1169\s
2026-02-16T12:00:49.8644789Z ruleset                                          
2026-02-16T12:00:49.8645012Z suppresswarnings                                 KEEP
2026-02-16T12:00:49.8645244Z appversiontemplate                               ?.?.?.?
2026-02-16T12:00:49.8645493Z updatebuildnumber                                True
2026-02-16T12:00:49.8646139Z appfilenametemplate                              %APP_PUBLISHER%_%APP_NAME%_%APP_VERSION%_%BC_TYPE%_%BC_VERSION%_%BC_C…
2026-02-16T12:00:49.8646461Z alcodeanalyzer                                   
2026-02-16T12:00:49.8646697Z ignorepragmas                                    
2026-02-16T12:00:49.8646927Z enable_external_rulesets                         False
2026-02-16T12:00:49.8647169Z showmycode                                       Keep
2026-02-16T12:00:49.8647566Z resourceexposurepolicy_allowdebugging            Keep
2026-02-16T12:00:49.8647827Z resourceexposurepolicy_allowdownloadingsource    Keep
2026-02-16T12:00:49.8648118Z resourceexposurepolicy_includesourceinsymbolfile Keep
2026-02-16T12:00:49.8648550Z internalsvisibleto                               Keep
2026-02-16T12:00:49.8648779Z preprocessorsymbols                              
2026-02-16T12:00:49.8649779Z generatereportlayouts                            True
2026-02-16T12:00:49.8650025Z applicationinsightskey                           
2026-02-16T12:00:49.8650285Z alcachepath                                      C:\agents\_work\1169\s
2026-02-16T12:00:49.8650536Z publishartifact                                  False
2026-02-16T12:00:49.8650767Z publishxlif                                      False
2026-02-16T12:00:49.8651017Z failonwarnings                                   False
2026-02-16T12:00:49.8651241Z failonany                                        False
2026-02-16T12:00:49.8651460Z storageaccount                                   
2026-02-16T12:00:49.8651694Z sastoken                                         
2026-02-16T12:00:49.8654791Z printappmanifest                                 True
2026-02-16T12:00:49.8655001Z outputalclogs                                    True
2026-02-16T12:00:49.8655194Z additionalprobingpaths                           
2026-02-16T12:00:49.8655390Z allowed_publisher_names                          
2026-02-16T12:00:49.8655608Z allowed_publisher_names_separator                ,
2026-02-16T12:00:49.8655810Z accept_insider_eula                              True
2026-02-16T12:00:49.8656009Z track_source_build_metadata                      True
2026-02-16T12:00:49.8656234Z alc_continuebuildonerror                         False
2026-02-16T12:00:49.8656429Z alc_errorlog                                     False
2026-02-16T12:00:49.8656623Z pwsh                                             True
2026-02-16T12:00:49.8656695Z 
2026-02-16T12:00:49.8656770Z 
2026-02-16T12:00:49.8723790Z True
2026-02-16T12:00:49.9211966Z *** For documentation, please visit   : https://www.alops.be/documentation
2026-02-16T12:00:49.9218313Z 
2026-02-16T12:00:50.3625334Z *** ALOps License:
2026-02-16T12:00:50.3640521Z   * Licensed To: Dynamics Consultants	(Per Run License)
2026-02-16T12:00:50.3645533Z 
2026-02-16T12:00:50.6039614Z *** Importing required Task-Functions
2026-02-16T12:00:51.4516639Z 
2026-02-16T12:00:51.5011606Z *** Artifact Type   : [sandbox]
2026-02-16T12:00:51.5017237Z *** Artifact Version: []
2026-02-16T12:00:51.5023221Z *** Artifact Country: [GB]
2026-02-16T12:00:51.5028800Z *** AL Source Path  : [C:\agents\_work\1169\s]
2026-02-16T12:00:51.5034721Z *** AL Cache Path   : [C:\agents\_work\1169\s]
2026-02-16T12:00:51.5041186Z 
2026-02-16T12:00:51.5084204Z 
2026-02-16T12:00:51.5881168Z *** Default Working Folder: C:\agents\_work\1169\s
2026-02-16T12:00:51.5887857Z *** Artifact Folder       : C:\agents\_work\1169\a
2026-02-16T12:00:51.5895084Z *** Agent Tool Folder     : C:\agents\_work\_tool
2026-02-16T12:00:51.5902534Z *** Agent Temp Folder     : C:\agents\_work\_temp
2026-02-16T12:00:51.5911342Z *** Agent Tools Folder    : C:\agents\_work\_tool
2026-02-16T12:00:51.5916927Z 
2026-02-16T12:00:51.5960421Z *** Resolving Path: [C:\agents\_work\1169\s]
2026-02-16T12:00:51.6017819Z *** AL Source Folder      : C:\agents\_work\1169\s
2026-02-16T12:00:51.6026814Z *** Resolving Path: [C:\agents\_work\1169\s]
2026-02-16T12:00:51.6048305Z *** AL Cache Folder       : C:\agents\_work\1169\s
2026-02-16T12:00:51.6054557Z 
2026-02-16T12:00:51.6075755Z *** Check BcContainerHelper
2026-02-16T12:00:51.8883851Z *** Load BcContainerHelper
2026-02-16T12:00:52.1805941Z BcContainerHelper version 6.1.7
2026-02-16T12:00:53.4232825Z BC.HelperFunctions emits usage statistics telemetry to Microsoft
2026-02-16T12:00:54.4154807Z Running on Windows, PowerShell 7.5.4
2026-02-16T12:01:10.8545573Z 
2026-02-16T12:01:10.8551440Z 
2026-02-16T12:01:10.9416365Z ##[command]"Get-BCArtifactUrl" 
2026-02-16T12:01:10.9417041Z Name                           Value
2026-02-16T12:01:10.9417456Z ----                           -----
2026-02-16T12:01:10.9417700Z type                           sandbox
2026-02-16T12:01:10.9418070Z country                        gb
2026-02-16T12:01:10.9418763Z accept_insiderEULA             True
2026-02-16T12:01:10.9419172Z select                         Weekly
2026-02-16T12:01:10.9419433Z 
2026-02-16T12:01:10.9419722Z 
2026-02-16T12:01:11.5075282Z Downloading Platform index to C:\agents\_work\_temp\bcContainerHelper.platform.json
2026-02-16T12:01:11.8988367Z Downloading gb index to C:\agents\_work\_temp\bcContainerHelper.gb.json
2026-02-16T12:01:12.3565132Z Downloading Platform index to C:\agents\_work\_temp\bcContainerHelper.platform.json
2026-02-16T12:01:12.5867394Z Downloading gb index to C:\agents\_work\_temp\bcContainerHelper.gb.json
2026-02-16T12:01:13.5815671Z Downloading artifact /sandbox/27.4.45366.46217/gb
2026-02-16T12:01:13.5937642Z Downloading C:\Users\BuildUser\AppData\Local\Temp\7f6fc3ed-413b-416c-99f3-9619e73fda35.zip
2026-02-16T12:02:22.3556697Z Unpacking artifact to tmp folder using Expand-Archive
2026-02-16T12:02:31.6742544Z *** Platform: c:\bcartifacts.cache\sandbox\27.4.45366.46217\platform
2026-02-16T12:02:31.7053964Z *** Localisation: c:\bcartifacts.cache\sandbox\27.4.45366.46217\gb
2026-02-16T12:02:36.4319325Z *** VSIX Path: C:\bcartifacts.cache\sandbox\27.4.45366.46217\platform\ModernDev\pfiles\microsoft dynamics nav\270\al development environment\ALLanguage.vsix
2026-02-16T12:02:36.8968211Z   * Extracting VSIX to temporary path [c:\bcartifacts.cache\sandbox\27.4.45366.46217\VSIX-Temp]
2026-02-16T12:03:12.6682687Z   * Rename temporary VSIX Path [c:\bcartifacts.cache\sandbox\27.4.45366.46217\VSIX-Temp] => [c:\bcartifacts.cache\sandbox\27.4.45366.46217\VSIX]
2026-02-16T12:03:13.0620307Z ##[error]Access to the path 'C:\bcartifacts.cache\sandbox\27.4.45366.46217\VSIX-Temp' is denied.
2026-02-16T12:03:13.1288797Z *** PWSH Run Completed: 1
2026-02-16T12:03:13.1769456Z ##[section]Finishing: ALOps App Compiler - Weekly Build

Expected behavior
The step will run without erroring

[mtraxinger]

I agree on this one. We see it all the time. Just add a simple backoff to wait until the lock is released. The next pipeline run always works and I've never seen the lock be present more than a couple of seconds after the failure.

[waldo1001]

It shouldn't happen.

I can only imagine this would happen on a server with multiple agents - or a server where the virus scanner is locking the file/folder.. .

Could you verify that?

[mtraxinger]

I can't speak for David obviously. For us it's multiple build agents on the same server. I know it's not best practice, but we're also not going to increase build times by 400% and increase Azure costs to be best practice for something that works great 99% of the time. I don't think a back off of trying to delete the temp folder is bad even with this setup. Not even sure it should be a true failure to be honest.

[DavidCurd]

We have Microsoft Defender enabled AND multiple build agents. We only added the second build agent this year though and had identified it causing this issue once. Assuming it's Microsoft Defender causing the issue most of the time, is the below still the recommended solution?

variables:
- name: 'alops_disable_amsi'
  value: true

I think the multiple build agents is less of an issue for us, but I guess we could probably use the Agent.HomeDirectory predfined variable to give each agent it's own cache. Not the best use of disk space, but it would stop the errors.

[waldo1001]

I don't think the Agent.HomeDirectory will solve it all. The compiler, bcch, artifacts, .. all use the same folders, so files will be locked, and you will have those kind of issues.

But like @mtraxinger said - it works "most" of the times, so is it really an issue.

Do know we do not intend to do anything about it, also because we can never guarantee how Microsoft will act on these kind of things.. .

[mtraxinger]

I think anything that causes a user to have to rerun a build for something that could be avoided is an issue.

I'd also settle for a separate task that creates the VSIX folder. That way I could potentially act accordingly if it fails because of a lock. When it's in the middle of the compile step there's not much to be done.

[DavidCurd]

I think we can prevent 90% of the errors by excluding the path from AV so I've created an exclusion and will see how we get on. Thanks for your help.

[waldo1001]

I think anything that causes a user to have to rerun a build for something that could be avoided is an issue.

Well, the cause is that you have multiple agents on one server - it's a simple fix.

When I look into documentation, this is not "just" ALOps .. it's a common "bad practice", which only seem to work well in deployment scenarios, but not in these.

Key pitfalls (and how to avoid them)

• Workspace collisions
• Tooling conflicts (SDKs, npm caches, ports)
• Resource contention