Unable to open repository error on Windows XP

Question

I'm trying to commit to my local SVN which has been working just fine, but today its giving this error:

Unable to open repository 
'file:///C:/wamp/www/svns/[myproject]/[dir]/[subdir]'

What could be the problem?

Edit: full error:

Commit failed (details follow):
Unable to open an ra_local session to URL
Unable to open repository 
'file:///C:/wamp/www/svns/[myproject]/[dir]/[subdir]'

Second Edit:

Here is the TortoiseSVN and SVN client info:

TortoiseSVN 1.5.7, Build 15182 - 32 Bit , 2009/01/24 22:44:13
Subversion 1.5.5, 
apr 1.2.12
apr-utils 1.2.12
berkeley db 4.4.20
neon 0.28.3
OpenSSL 0.9.8i 15 Sep 2008
zlib 1.2.3

Answer 1

Have you upgraded one or more of your subversion clients recently?

All your clients should be at the same level (All 1.4., all 1.5., or soon all 1.6.*) if they access your repository directly.

Technically you can get away with some other combinations, but as you need them to be the same version for your workingcopies too, you should just make them compatible... (Before 1.5.X releases your repository was automatically upgraded to the latest version when you access them with a later version).

Another thing to look out for is that not all clients support the same repository formats. Most support fsfs, but not all support BDB. And to make things worse there are multiple incompatible BDB versions....

TortoiseSVN, AnkhSVN and Slik Subversion have exactly the same BDB versions at the same 1.X.Y level.. For other clients you should read their documentation

Small update: TortoiseSVN 1.6.x will drop support for file:// access to BDB repositories. (You will then need a svnserve or apache server to access these repositories)