I have been trying to fix the instant validation problem, https://moodle.org/mod/forum/discuss.php?d=269665 ,
and this led to the discovery that now STACK has trouble with some of the diagnostics involving square roots. (See screen shot.) (It does pass the basic health check.)
I have caching turned off. I have platform type set to Linux. (Not optimized.) Its slow but probably better for debugging.
I installed the latest STACK, 3.3.1 this morning, but that didn't solve this problem.
I thought that maybe the problem is I am using an old version of Maxima, version 5.23.2, and while STACK claims to support this version, I thought maybe if I updated to STACK's default of 5.31.1things would get better.
But that is turning out to be not so easy. (I am on a Hostmonster VPS server, running Centos 6.5.)
I added the EPEL repository. But the yum utility can't find any version of Maxima higher than 5.23.2.
I got the maxima-5.31.1-1.i386.rpm file from SourceForge, but its installation fails, with errors:
$ sudo yum install ./maxima-5.31.1-1.i386.rpm
[sudo] password for halverph:
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
* rpmforge: mirror.webnx.com
Setting up Install Process
Examining ./maxima-5.31.1-1.i386.rpm: maxima-5.31.1-1.i386
Marking ./maxima-5.31.1-1.i386.rpm as an update to maxima-5.23.2-1.el6.x86_64
Error: Nothing to do
What should I do??