I had to Open the
sln
file with a simple text editor.
and searched for my project that did not find, and corrected the directory path.
Project("{XXXX-XXXXX-XXXX}") = "PECeShopSame",
"Dir1\PECeShopSame\PECeShopSame.csproj", "{XXXX-XXXXX-XXXX}"
Reference[
^]