Yes, the 1.10 IDE should work fine, it needs to be copied into your /blitzmax 1.12 directory I would rename it MaxIDE1.10 before moving.
If that doesn't work you need to check the permissions of the 1.12 binaries, go to a terminal, cd to 1.12's bitzmax/bin folder and type
./bcc
Which will test the blitzmax compiler and if successful print a version, and if not hopefully an error message about permissions which you need to deal with
then back up a directory (cd ..) and type ./MaxIDE which will test the 1.12 IDE and again hopefully you will be treated to an informative error message which may help you to proceed.
If that doesn't work you need to check the permissions of the 1.12 binaries, go to a terminal, cd to 1.12's bitzmax/bin folder and type
./bcc
Which will test the blitzmax compiler and if successful print a version, and if not hopefully an error message about permissions which you need to deal with
then back up a directory (cd ..) and type ./MaxIDE which will test the 1.12 IDE and again hopefully you will be treated to an informative error message which may help you to proceed.