Users & 'Full Control' site collection admin are unable to EDIT items.
Error message reads:
The query cannot be completed because the number of lookup columns it contains exceeds the lookup column threshold enforced by the administrator
I understand how this issue is normally triggered - if more than 8 lookup columns (I've also read of a max of 12) are used, it creates an error. I'm using SP2013.
However, in my scenario, the list in question is long-established and is stable (in terms of development - no new lookup columns are in use). Hence, I'm somewhat puzzled as to what has triggered this error.
I'm using content types, one of these only has 6 lookups in it, I tried to edit one of these but I get the same error.
I did have some Windows Updates install yesterday, I've no idea if that would be the cause. Windows Updates are regular, so normally I'd exclude it as being the cause of anything, but given the otherwise stable nature of the list, I've been trying to think up other possible causes.
Product content type pic:
8 lookups/'person or group' columns
Other EXP content type pic:
Only 6 lookups/'person or group' columns
23/09/2019 - additional info
a different farm administrator to me could still edit items, while I could not (despite us having identical permissions). Suggesting he does not have the latest Windows Updates installed yet(?)
Following Peter's recent comment regarding workarounds. In my 'OTHER EXP' content type, which has 6 'Lookup' or 'Person or Group' fields, I went in CT settings and hid a lookup field, so only 5 of these field types remain in the edit form; the edit form worked correctly. However, for the 8 field Product content type, this workaround did not help
On the server, in Sharepoint Central Administration, I observed that the default number of lookup fields is set to 8. Therefore this setting is somehow being overriden, since the List will not display the edit item form.
Not all lists are affected; in a different site collection a list with 7 lookups is still functioning normally.
24/09/2019 - in response to Slaven's comment about database version:
Database version is 15.0.5023.1000:
Saved the list as a template with contents, with the intention of trying to recreate it. When I tried to create a new list (including contents) based on this template, I got this (Windows?) error.
This website lists lots of error codes for Microsoft tech, wow what a find, specifically it included my error message too. I'm using Windows 7, my colleagues are using newer versions of Windows.