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![](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(28.799999999999997, 11%, 12%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ETD%3C/text%3E%3C/svg%3E)
I have a project produced in Visual Studio 2017. I have just downloaded Visual Studio 2022 and tried to open the project. Although all of the code can be viewed, I can't see any of the Forms. I get:
"The Designer could not be shown for this file because none of the classes within it can be designed. The designer inspected the following classes in the file: StartForm - the Base class 'System.Windows.Forms.Form' could not be loaded. Ensure that the assembly has been referenced and that all projects have been built."
Can someone please explain this and offer a solution?
![](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(233.6, 28.999999999999996%, 32%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EXZ%3C/text%3E%3C/svg%3E)
Hi @Trevor Daniels ,
Did you design your app with the "Any CPU" option? It will cause your code to JIT to 32-bit on 32-bit platforms and 64-bit on 64-bit platforms.
More details you can refer to Visual Studio designer in x64 doesn't work
Hope it could be helpful.
Hi @Trevor Daniels ,
Do you still meet this issue? Please let me know if you need further help.
I do still have the issue. The original project in VS2017 is set to any CPU and this is a 64bit system. In vs 2017 everything works fine.
This morning I opened the project in vs2017, then opened it in vs2022. The project worked great in vs2022, including all the forms. I closed it down and repeated the process and it returned to the original problem with the forms designer; consequently I'm giving up on vs2022 !!!
![](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(112.00000000000001, 61%, 20%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EJS%3C/text%3E%3C/svg%3E)
any word on this being fixed? the main 2022 is out this morning and i can't open ANY winform that inherits from any base class. Even ones in the same solution.
says it can't find XYZ base class etc.
![](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(38.4, 1%, 13%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EEV%3C/text%3E%3C/svg%3E)
Same for me, I have a form class derived from 'System.Windows.Forms.Form' and cannot open any winform in my project.
Stuck in Visual studio 2019, here non problem
![](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(6.4, 64%, 10%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EFZ%3C/text%3E%3C/svg%3E)
Hey dears,
is there any solution for that? am also having same error. designed the forms using VS2019. sometimes it opens the forms in designer but trying from the morning but failed to load it with the same error. what to 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(208, 25%, 30%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EJC%3C/text%3E%3C/svg%3E)
I'm having the same issue.
I tried to open the forms designer in VS2022 but it shows error "Base Class could not be loaded".
There were no issue in VS 2017 or VS2019.
Any solution for this?
![](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(313.6, 33%, 40%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESD%3C/text%3E%3C/svg%3E)
Any news on this. Visual Studio 2022 was released and the issue persists.
![](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(204.8, 83%, 29%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EHL%3C/text%3E%3C/svg%3E)
I have this problem in latest VS20222 of today.
I have created and shared a solution to show the problem.
In this solution both FormMain and FormMiddle causes designer to show error when you try to design these.
![](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(147.20000000000002, 95%, 24%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ESD%3C/text%3E%3C/svg%3E)
I have derived / inherited forms that I successfully created and edited in a previous version of VS2019 that I can no longer edit in the latest update of VS2019 (v16.11.13) nor in VS2022 (v17.1.6). I'm screwed until or unless this bug is fixed.
Please try to :
This worked for me
![](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(182.40000000000003, 19%, 27%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EBC%3C/text%3E%3C/svg%3E)
This did not work for me.
It is unbelievable that Microsoft has allowed this bug to go unfixed for so long! I cannot edit any designer in Winforms or our reporting software (active reports) if the form/report inherits from a base class.
![](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(64, 69%, 16%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAW%3C/text%3E%3C/svg%3E)
This worked for me as well.
Hi @Trevor Daniels ,
Try closing/reopening the designer in vs2022.
It seems to be a known problem with vs2022
Besides, since VS2022 is still in development and testing, you can download it after the official version is released.
Best Regards,
Xingyu Zhao
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Has there been a solution that works for this .. I am having the same issue with vs2019 project... unable to view the design page ... Everything else so far is working well with VS2022
The project builds and loads just not able to see the design page.
Good luck to the DEV team working on release version of VS2022
Mark
i have the same issue with the full 2022 pro they released this morning. no winform that inherits from another one will view in the designer.
always says "can't find xyz base class etc" with the yellow error header and that's it. even forms in the SAME project as the base won't open.
![](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, 73%, 18%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ENS%3C/text%3E%3C/svg%3E)
Seeing this same issue on a VS2019 project. App compiles and runs fine, but opening any form in the designer throws a "The base class 'System.Windows.Forms.Form' could not be loaded. Ensure the assembly has been referenced and that all projects have been built. " error. I tried to take the suggestion of the error message and did a "rebuild solution", but it didn't make a difference.
![](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(137.6, 7.000000000000001%, 23%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EKI%3C/text%3E%3C/svg%3E)
Just downloaded VS2022 and got this error. For me the x86 compilation is not working for designer and gives errors, but "Any CPU" does work.
VS2019 is working perfectly as before.
![](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(147.20000000000002, 80%, 24%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECH%3C/text%3E%3C/svg%3E)
Thats a worry. I have no choice but to compile my solution in x86 because of old components.