On 1 September [[ https://commons.wikimedia.org/wiki/Commons:Wiki_Loves_Monuments_2018 | Wiki Loves Monuments ]] is going to start again. Users have reported a severe bug: in step 4 (describe) the [[ https://www.mediawiki.org/wiki/Extension:UploadWizard/Campaigns | upload campaign ]] goes completely blank.
{F25457239}
Normally people fill in the description, categories, coordinates, and other information. This bug now suddenly appears, while nothing has been changed in the upload campaigns.
This problem occurs in bot the latest Firefox as Chrome.
Just for Wiki Loves Monuments we use 146 campaigns!
By testing I discovered that if I [[ https://commons.wikimedia.org/w/index.php?title=Campaign:wlm-test&diff=prev&oldid=317176434 | remove the part ]] of the [[ https://www.mediawiki.org/wiki/Extension:UploadWizard/Campaigns#defaults |defaults ]], the error is solved and everything works perfectly.
The defaults part is used in almost every upload campaign we have and makes sure there is a basic categorisation available on all the files.
Please fix this bug before 1 September, this is a vital part of the infrastructure of Wiki Loves Monuments.
(Feel free to test the upload campaign(s) in [[ https://commons.wikimedia.org/wiki/Campaign:wlm-test | Campaign:wlm-test ]].)