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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.
@Zach Sim , Welcome to Microsoft Q&A, you could try the following advice to check if it works for you.
@Zach Sim , is any update?
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)
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)
Thanks. This worked!
Could find "Microsoft.Office.Interop.Excel" in your GAC path?
Reference below path:
@ShuaiHua Du The package is installed and in the correct location, and included in the project through Nuget.
Moved my comment to top of thread
![](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)
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)
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.