Hot to add validation of folder names in CMS5 filemanager

After migration of a CMS4 site we started to get a lot of reports of links that had stopped working.

I remembered that we had trouble with non allowed characters in an other site some time ago.

A quick check and sure enough we had a problem with “&” characters in some of the folder names.

In CMS 6 a validation has been added to avoid these problems but not in a default CMS 5 R2site.

Luckily there is an easy fix. Replacing the standard

<virtualPath customFileSummary="~/FileSummary.config" /> row in web.config with the below adds the validation.

<virtualPath customFileSummary="~/FileSummary.config"  illegalCharactersRegex="%|&amp;|\+|/COM[0-9]([/\.]|$)|/LPT[0-9]([/\.]|$)|/PRN([/\.]|$)|/CLOCK\$([/\.]|$)|/AUX([/\.]|$)|/NUL([/\.]|$)|/CON([/\.]|$)|/.+\.$" illegalCharactersDisplayString="%,&amp;,+,COM,LPT,PRN,CLOCK$,AUX,CON,NUL,*.">

I don’t understand why this functionality isn’t activated by default in  CMS5 and a recommendation to anyone upgrading a pre CMS5 site is to go through all the folders and correct any incorrect folder names.