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Help! Applying a patch broke my dev instance.

  • September 18, 2026
  • 9 replies
  • 53 views
MichaelShirk
Captain II
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Using patch tool version 1.18.1.0. I attempted to update my developer instance

from  26.100.0175 to 26.100.0175.5  

I don’t recall seeing an error in the terminal, but I also don’t recall closing the terminal. 

I went to load the site and got the following server error. “ The type or namespace name 'Maintenance' does not exist in the namespace 'PX.Data' (are you missing an assembly reference?)” 
 

 

After some digging I discovered that PX.Data.dll was missing from my instance bin folder. 

The patch tool errors now if I try to run any of the commands. 

 

Attempting to run the wizard to upgrade/repair the site also errors on PX.Data.dll. 

 

Anyone else seen anything like this?

Michael Shirk, Pine View Buildings, LLC - If a member helped you, please *Like* their post. If a member provided an answer to your question, please mark it as *Best Answer*.

9 replies

JKurtz29
Varsity II
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  • JKurtz29
  • Varsity II
  • September 18, 2026

I haven’t seen that.  Have you tried going into the ERP Configuration Wizard and use the Perform Application Wizard and selecting the option to upgrade the website?  That should write the files back out to the website.

Once you get back in, you can try patching again, and republishing your customizations.

Jerry Kurtz | Senior Director Application Development | JKurtz@algorithminc.com
MichaelShirk
Captain II
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  • MichaelShirk
  • Author
  • Captain II
  • September 18, 2026

​@JKurtz29 Perhaps you were typing your response when I updated the post to add that I’ve already tried that!😅

Michael Shirk, Pine View Buildings, LLC - If a member helped you, please *Like* their post. If a member provided an answer to your question, please mark it as *Best Answer*.
JKurtz29
Varsity II
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  • JKurtz29
  • Varsity II
  • September 18, 2026

​@JKurtz29 Perhaps you were typing your response when I updated the post to add that I’ve already tried that!😅

Or I was just lazy and didn’t read it all :/

I imagine you’ve also tried doing an IISRESET from and administrator command prompt or rebooted your machine to recycle IIS in case it somehow has a file handle in memory or some other strange thing going on?

Have you also tried adding a new instance in a different folder, but pointing to your existing database to see if that works?

Jerry Kurtz | Senior Director Application Development | JKurtz@algorithminc.com
Acumatica Employee
  • andreybudaev87
  • Acumatica Employee
  • September 18, 2026

Hi ​@MichaelShirk 

 

After PatchTool performs any operation, a log file is written to the disk. Please attach it. 

darylbowman
Captain II
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Did you try just pasting in PX.Data.dll from a different 26 R1?

Daryl ⚡Freelance developer 🛒Check out my products 👉🏻deftstrokesdev.com/index.php/products ⏩linkedin.com/in/darylbowman
MichaelShirk
Captain II
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  • MichaelShirk
  • Author
  • Captain II
  • September 18, 2026

​@JKurtz29  Those are the things I’m in the process of trying. 

Thanks! 

​@andreybudaev87 Where do those get stored?

Michael Shirk, Pine View Buildings, LLC - If a member helped you, please *Like* their post. If a member provided an answer to your question, please mark it as *Best Answer*.
Acumatica Employee
  • andreybudaev87
  • Acumatica Employee
  • September 18, 2026

​@MichaelShirk 

 

In the folder with patchtool.exe

MichaelShirk
Captain II
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  • MichaelShirk
  • Author
  • Captain II
  • September 18, 2026

​@darylbowman I tried that, but even with admin permissions I was still blocked. 
Claude and ​@JKurtz29 seem to be right, because after a reboot I could rebuild the site and it loads again. 

“

When a file is deleted while a process still holds an open handle to it, Windows puts it in a delete-pending state: the name disappears from directory listings, but the entry stays reserved in the directory until the last handle closes. Any attempt to create a new file with that name returns ERROR_ACCESS_DENIED, which .NET surfaces as UnauthorizedAccessException. That matches everything you've seen — invisible file, writable folder, clean ACL, test.txt succeeds, PX.Data.dll doesn't.

Reboot the server, then retry the copy. That releases the handle unconditionally and is faster than hunting it down.

” 

I’ll reattempt the patch now.

Michael Shirk, Pine View Buildings, LLC - If a member helped you, please *Like* their post. If a member provided an answer to your question, please mark it as *Best Answer*.
MichaelShirk
Captain II
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  • MichaelShirk
  • Author
  • Captain II
  • September 18, 2026

​@andreybudaev87 the second attempt did exactly the same thing. 
I’ve attached the log file. 

I ran the patchtool. The process looked like it was running successfully, then suddenly powershell closed. 

I try to open the site and it’s broken again with the same message. 
I checked and PX.Data.dll is also missing from the instance bin folder again. 

 

Michael Shirk, Pine View Buildings, LLC - If a member helped you, please *Like* their post. If a member provided an answer to your question, please mark it as *Best Answer*.
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