4,384 questions
Could find "Microsoft.Office.Interop.Excel" in your GAC path?
Reference below path:
How to setup Excel Interop for Exccel 365
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(121.6, 43%, 21%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EZS%3C/text%3E%3C/svg%3E)
Zach Sim
26
Reputation points
I've been attempting to setup a project that allows me to use Excel Interop in C# on the Office 365 version (I need to create and edit some sheets to automate some tasks from work involving CSV files). However almost every attempt has resulted in the following error...
Unhandled exception. System.IO.FileNotFoundException: Could not load file or assembly 'office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'. The system cannot find the file specified.
File name: 'office, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'
at Program.<Main>$(String[] args)
I get that I'm missing an assembly or dll however I have no idea how I could fix it. I've attempted multiple solutions, adding various references and packages however I've had almost no success.
I only have 365 installed on this machine and what confuses me more is that by reverting to version 12.0.4518.1014 and installing a third party package simply called "Office" from NuGet, the project mostly works, aside from it telling me to use .Net Framework 4.8 instead of .Net Core 6.0
I've also had some others report that for some reason they can't get the version of interop to function with Office 365. Is there some step or package that we're missing?
I'm currently using Visual Studio 2022 with the Microsoft.Office.Interop.Excel package in C#, It's a simple console app. if any other information is needed feel free to ask.
Microsoft 365 and Office | Development | Other
Developer technologies | C#
11,579 questions
{count} votes
-
Jack J Jun 25,296 Reputation points2022-07-25T06:25:38.417+00:00 @Zach Sim , Welcome to Microsoft Q&A, you could try the following advice to check if it works for you.
- Please try to install nuget-package Microsoft.Office.Interop.Excel.
- You could add Microsoft Excel 16.0 Object Library in the COM option.
-
Jack J Jun 25,296 Reputation points
2022-07-29T02:06:27.52+00:00 @Zach Sim , is any update?
-
Zach Sim 26 Reputation points
2022-08-03T22:40:03.457+00:00 Apologies @Jack J Jun I've been very busy
Checking through your solution I've noticed that I don't the Object Library anywhere on my PC that I can find, do you know where I could install this?
As for the Interop package I already had that installed through nuget, swapping between versions as mentioned was not working except for the 12.0 version with the 3rd party package. -
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(25.6, 92%, 12%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EO%3C/text%3E%3C/svg%3E)
Ottomatica 0 Reputation points2023-09-02T17:40:58.2766667+00:00 I get the same error with Microsoft Visual Studio Community 2022 (64-bit) - Current
Version 17.7.2
I have Office 365 as well.
On my work PC with VS 2017 and Office 16 I do not get the same error.
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(22.400000000000002, 54%, 12%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERJ%3C/text%3E%3C/svg%3E)
Ramya Jayaram 5 Reputation points2024-04-30T10:12:26.2+00:00 Thanks. This worked!
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(48, 78%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EEI%3C/text%3E%3C/svg%3E)
Emmanuel Idun 0 Reputation points2024-07-05T19:43:39.39+00:00 @Ramya Jayaram what exactly worked for you? What did you do?
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(163.2, 95%, 25%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EMC%3C/text%3E%3C/svg%3E)
moacir chiarello 0 Reputation points2025-03-24T19:21:01.37+00:00 The solution is simple Install microsoft.office.core in your nuget project!
Sign in to comment
3 answers
Sort by: Most helpful
-
ShuaiHua Du 636 Reputation points2022-07-25T05:53:26.283+00:00 -
Zach Sim 26 Reputation points
2022-08-03T22:40:47.577+00:00 @ShuaiHua Du The package is installed and in the correct location, and included in the project through Nuget.
-
Ottomatica 0 Reputation points
2023-09-02T17:33:58.18+00:00 Moved my comment to top of thread
-
moacir chiarello 0 Reputation points
2025-03-24T19:20:28.11+00:00 The solution is simple Install microsoft.office.core in your nuget project!
Sign in to comment -
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(83.2, 95%, 18%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EPZ%3C/text%3E%3C/svg%3E)
peiye zhu 165 Reputation points2023-09-03T03:03:32.5066667+00:00 as to .Net Core 6.0,How about openxml.package to handle Excel file?
-
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(51.2, 77%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ERM%3C/text%3E%3C/svg%3E)
Richie Mathison 0 Reputation points2024-05-01T15:04:18.05+00:00 There is a warning message in here that is highlighted purple like the one that says we "Microsoft" does not support this check the product lifecycle. Have you seen that one? Well the other one I saw says it does not work because of the 64-bit conversion and 2019 was the last edition that worked. 2022 is 64-bit so it said the use the ACE. It really has no code sample that I could find so I asked a separate question.