Hi, this is Beda, I'll help you resolve this (I hope).
I need to confirm the issue again.
1. You are reporting a Compatibility problem with Toolset Views and a plugin called AppPush, which apparently has been introduced with View the last Views version, as I can see here https://toolset.com/forums/topic/toolset-views-causes-many-internal-server-error/#post-1456391
Meaning, Toolset Views 3.0.2, released January 8, 2020, was the update that broke things.
Is this correct?
Reverting to any previous Views version solves the issue?
You can download previous Views here to test with
https://toolset.com/download/toolset-views/#changelog
2. The problem consists in “Internal Server Error” when you activate both Views and AppPush plugin at the same time, correct?
Those “Internal Server Error” then later turned out to be the errors posted here:
https://toolset.com/forums/topic/toolset-views-causes-many-internal-server-error/#post-1463461
OR, are those errors gone? Because I can read there, it says "I increased the Memory limit & the page worked fine....so kindly ignore the previous post."
Hence I am not sure, do those errors still happen?
If this is correct, and the errors still happen, please proceed as follows (best, on a testing site, if you have none, only after a valid backup on the live site)
1. Deactivate all plugins and change the theme to Twenty-Twenty. Make sure you use no cache, no Must Use and no Drop-In Plugins
2. Delete the contents of your debug log, and make sure from now on WP Debug is active for the next test
3. Re-activate only Toolset Views and the plugin you suspect it conflicts with (AppPush)
If the error happens, at this point, note down the steps you took, and send me that Debug Log file generated.
Then, you can proceed and re-enable all plugins and theme as needed on your site.
Please then also attach the steps to install, and use AppPusher plugin on a clean/fresh website.
I need those precise steps, and eventual keys or subscriptions if I need to register it, or the resource where I can gather those from the 3rd party eventually, because I am not familiar with this 3rd party app, and because to fix anything we need to replicate it first on a controlled instance.
I see we have a total of 24 users using AppPush, so it is very likely that some compatibility issue exists and no one yet reported it.
It however also means we have no active links to the Plugins authors, as only a very few Toolset users use it yet
Any data you can provide for us to replicate this issue on a fresh WP Install will expedite the resolution time for this.
PS:
I cannot do the tests online on the live site myself, you'd need to either provide us with a copy, or a staging instance or, written permission to make any change on the live site and a valid backup (we cannot create those for you).
