-I have a weird case happened to me sometimes, I have a huge form developed on nintex form, sometimes when I submit the form, it does not submit, it reloads the form and empty all the inserted fields, there is no errors in console, the button type is save and submit, it happens sometimes not always, does it related to the data size? or some token timeout??
-Another issue, I develped a custom upload, and I use sharepoint service to upload it to some list, when I take too long to fill the form, the service refuses to upload, it give me ana exception
see the following screenshot
I know this is a sharepoint issue, but if anyone can help would be appreciated.
for your first issue, did you have a look at the ULS logs? If we have no error information at all it may be impossible to fix the issue, especially if it only occurs sometimes. See if you find anything suspicious in the ULS logs, especially about timeouts etc.
For your second issue, can you show us how you developed the custom upload? At first glance it looks like a permission-related issue.