For a few months now, whenever I've opened a solution in the new Visual Studio 2022 SDK plugin, I've been receiving the annoying warning that my project targets an unsupported version of .NET, asking me whether I want to upgrade the target to .NET 4.8.
It was a mere nuisance, usually clicked okay and could continue to work.
Starting October 1, however, this no longer worked. Directly after clicking OK, I would receive the error "Project Locked - Please check out the project before editing it". When confirming this error, the solution would revert to state "unloaded" and no files were shown, so I was unable to work.
SAP were clueless as well, they pointed me to SAP Note 3646437 - Target Framework not supported when opening a PDI Solution - SAP for Me, which I already knew. It recommends installing Visual Studio 2019, just for the .NET 4.0 targeting pack. I had already tried it, it hadn't removed the warning message and when I tried it again now, it didn't resolve the issue. Also, I hadn't changed anything, done no updates recently, so it would have been strange if this had worked.
Because I was completely blocked in my work, I tried desparate measures. I even reinstalled my Windows VM!
At one point, I thought I'd just install all targeting packs VS2019 provides - and what do you know - that did the trick! The annoying "targeting" message was gone, as well as the "Project Locked" error.
I tinkered some more. Turns out, all I needed to install from VS2019 was the .NET 4.8 targeting pack! So the instructions given in note 3646437 are incorrect. The note instructs to install the .NET 4.0 targeting pack - however, the missing component is actually the .NET 4.8 targeting pack. And this is included in VS2022! No need to install VS2019.
As you can see in my screenshot, I've only installed the core editor (Modeling SDK was already installed, probably by the standard installer) and selected the .NET Framework 4.8 targeting pack, nothing else.
I also have an assumption of what happened: Apparently, SAP forgot to upgrade the solutions to a supported targeting pack when the moved everyone to VS2022. Or they couldn't do it yet, because maybe VS2015 was incompatible with 4.8. So the advice in note 3646437, to install the (no longer supported) 4.0 targeting pack alongside ANOTHER version of VS2019, must have been a little embarrassing to them, I assume. After all, the only reason they made everyone upgrade to VS2022 was to avoid running the studio on unsupported software.
The obvious solution (even ChatGPT suggested it!) was to explicitly target 4.8 in the project file. That file can be found in the root of your local solution directory and ends in .myproj. Only problem is: If you do it yourself, the file will be immediatly overwritten once you log on to the solution and the project syncs from the server.
So what they probably did: At some point they just updated everyones project files to 4.8. At least I noticed that my project files contain added tags that read:
<TargetFrameworkVersion>v4.8</TargetFrameworkVersion>
<TargetFrameworkMoniker>.NETFramework,Version=v4.8</TargetFrameworkMoniker>
<TargetFrameworkProfile>
</TargetFrameworkProfile>
(I know because I was trying to tinker with this file myself before and didn't find any reference to the framework. Even after you click "Upgrade to 4.8" in the targeting error, the .myproj file remained without a reference to 4.8)
And because VS2022 (at least the core editor) installs WITHOUT .NET 4.8, the error occurred. The only thing that puzzles me is that the targeting error explicitly recommends and offers to upgrade to .NET 4.8 - even though .NET 4.8 is not installed.
Another puzzle piece that confirms my assumption: At first, only our DEV system showed this error. I could still load the TEST system without an issue. A few days later, the TEST system was affected as well - and what do you know? - it suddenly had the reference to .NET 4.8 in the .myproj file as well! I proceeded to check the original (non-patch) solution in our DEV system. Loaded correctly - and the .myproj file contained NO reference to any .NET version - and it still shows the "targeting" error when I load it - though I can just click it away as I used to be able to do before October 1.
Update: Just checked our PROD system. This one had not yet been upgraded by SAP, so I got the "targeting" message - but after clicking okay the solution was still unloaded. In this case I had to apply the solution provided in SAP note 3646437 (case 2, all the way at the bottom) and set Tools --> Options --> Source Control --> Plugin Selection to "None" to successfully load the project.