Now I'm not even able to open the project. If I try to do so, I get these errors:
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\Freespace2.vcxproj : error : Unable to read the project file "Freespace2.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\Freespace2.vcxproj(50,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 50, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\libjpeg.vcxproj : error : Unable to read the project file "libjpeg.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\libjpeg.vcxproj(50,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 50, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\liblua.vcxproj : error : Unable to read the project file "liblua.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\liblua.vcxproj(51,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 51, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\libpng.vcxproj : error : Unable to read the project file "libpng.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\libpng.vcxproj(49,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 49, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\zlib.vcxproj : error : Unable to read the project file "zlib.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\zlib.vcxproj(49,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 49, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\code.vcxproj : error : Unable to read the project file "code.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\code.vcxproj(49,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 49, position 2.
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\Fred2.vcxproj : error : Unable to read the project file "Fred2.vcxproj".
C:\Games\FreeSpace2\fs2_open\projects\MSVC_2011\Fred2.vcxproj(51,2): The project file could not be loaded. Name cannot begin with the '<' character, hexadecimal value 0x3C. Line 51, position 2.