I recently came across an error that looked like this:
'g_findconfigstringindex: overflow (2690): ' craftable_pap_1_shader'

This was on the Spongebob: Battle for Bikini Bottom map on coop online with some friends and I noticed some others had some issues as well. Listed are the solutions gathered:

1. Disable shaders that are causing the problem (if you are working on a map)
2. Check for extra files you have added (mod menus, hacks, textures, etc.)
3. Make sure you have the map fully updated (current update is 1.1 for Battle for Bikini Bottom)

It’s not “the shader” it’s bad menu code. Prob spamming the same value to dvar over and over