## WeBWorK Main Forum

### Re: Strange Problem Behavior

by Arnold Pizer -
Number of replies: 0
Hi Jason,

The images are stored using the md5 encoding of their TeX string. It is possible but with a very small probability for two different TeX strings to have the same md5 encoding. Originally when we did this WeBWorK checked to see if this occurred and handled things correctly if it did but I don't think we ever saw a case of it happening and I don't think this check is still in the code (I think John Jones at ASU put it in).

So try this. First save the offending image somewhere with its md5 name. Then remove all cached images and try viewing the problem again for the same person. See if you get the correct image. Then check the md5 name. You may have an example of two different short TeX strings having the same md5 encoding.

Arnie